HONEST STATUS: This is a demo deployment on Arbitrum One using play-money RUSD (faucet token). Contracts are pre-audit — Sourcify-verified, 163/163 forge + 38/38 integration tests green, but no external audit yet. Current max bet is 3,125 RUSD/hand, bond-limited (design target at $300M TVL: $520k–600k). One V1 incident is fully disclosed in the audit package. Credibility is the product — read the gaps before the claims.

WHITEPAPER — PROTOCOL EXTENSION PAPER v0.9

Draft for review · RAIN Protocol · parameters marked mutable are subject to governance ratification
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RAIN Risk Markets

Protocol Extension Paper — v0.95 (Draft for Review)

RAIN Protocol · Rain.one


"Traders buy risk. The Vault sells it. The Protocol prices it."


Abstract

RAIN began as a decentralized prediction market protocol: permissionless markets on real-world events, settled on-chain, with open liquidity and an SDK that lets any brand launch its own market frontend.

This paper specifies RAIN Risk Markets — a generalization of the same primitive to any quantifiable risk. A prediction market prices uncertainty about the world; a Risk Market prices uncertainty from any declared source of truth: a verifiable random function, a signed data feed, or a bonded oracle. All are instances of one activity: the transparent buying and selling of risk at a mathematically defined price.

The protocol itself takes no view on what the risk is about. A distribution is a distribution: the probability a random draw exceeds a threshold, the probability a flight lands late, the probability an index falls outside a band. Anyone may define a market on any distribution that passes the mathematical listing rules (§2); anyone may build a venue on top of it. One builder ships a high-frequency trading venue for synthetic risk; another ships parametric protection products for travelers or event organizers; a third ships classic prediction markets. Same primitive, same vault, same settlement — different frontends for different publics.

RAIN Risk Markets is a clearing house for risk positions:

The design goal is stated plainly: win on price. The protocol's cost structure (no intermediaries, no payment processing, no physical operations, no discretionary staff) permits a base spread of 1.25% (governance-adjustable within [0.5%, 2%]) — the lowest generalized price of risk offered across a full catalog of synthetic risk products — while sustaining competitive returns for liquidity providers and a real, volume-driven business for distribution partners.

A second design goal follows from the first: the deepest position capacity in the market. Because the risk book is carried by an open vault rather than a single operator's balance sheet, position limits scale linearly and transparently with vault TVL. At $300M TVL the protocol supports positions of $600,000 on even-money outcomes — exceeding the limits available at any centralized venue, physical or digital.


1. The Primitive

1.1 One definition covers every product

A Position is a tuple:

Position = { stake, distribution, payoutTable, spread }

A binary even-money draw, a uniform multiplier, a 36-to-1 single outcome, a heavy-tailed multi-outcome ladder, a threshold on a weather index, a delay on a scheduled flight — the protocol does not know product names. It knows distributions, payout tables, and spreads. This indifference is the core architectural property: the engine is product-agnostic and distribution-aware. Product identity — what a distribution is called, how it is rendered, whom it serves — lives entirely at the frontend layer (§7).

1.2 Relation to RAIN prediction markets

Prediction Markets Risk Markets
Source of uncertainty Real-world events Any declared truth source (§2.4)
Probabilities Discovered by trading Declared by the distribution
Settlement Oracle / resolver Truth-source proof
Counterparty Order book / AMM Risk Vault
Primitive Risk transfer Risk transfer

Same protocol family, same token, same brand/SDK distribution model, one thesis: RAIN prices risk. Any risk.

1.2b The risk continuum

Every risk-transfer industry — derivatives, insurance, reinsurance, prediction markets, gaming — performs the same operation: someone pays a spread over mathematical expectation to shed (or acquire) exposure to a distribution. The industries differ only in where the truth comes from and who is allowed to participate. The protocol organizes this as a continuum of truth sources, strongest first:

Cryptographic truth   (VRF proof)          → synthetic distributions — instant, exact
Parametric truth      (signed data feeds)  → indices: weather, flight status, prices
Economic truth        (bonded oracle game) → asserted real-world facts under stake

A position on a synthetic distribution converges in minutes; a parametric position settles the moment the index prints; an asserted fact settles through an optimistic assertion-and-challenge game (§2.4). The vault does not care: it prices spread against variance either way. This is why the protocol layer speaks only in expectation, variance, and truth sources — any narrower vocabulary would silently exclude most of the addressable market.

1.3 Why the statistics guarantee convergence

For a product with per-unit edge e and per-unit standard deviation σ, after n positions the expected trader loss is e·n while the noise is σ·√n. Expectation grows linearly; luck grows as a square root. The probability that aggregate trading ends profitable for the buy side falls below 5% when n ≈ (1.65·σ/e)² and below 1% at n ≈ (2.33·σ/e)².

At protocol scale — thousands of traders, millions of rounds — aggregate revenue is a deterministic function of volume:

Expected Vault PnL ≈ spread × volume

Every participant's share of that flow is therefore not a speculative bet but a statistical annuity, priced per round and paid per round.


2. Distribution Engine

2.1 MarketDefinition

Any market listed on the protocol is an on-chain object:

MarketDefinition {
  outcomes[]        // probabilities, summing to 1
  payoutTable[]     // multiple per outcome
  randomnessSource  // VRF config
  spreadCheck       // engine-verified: Σ(p·payout) ≤ 1 − minSpread
  exposureProfile   // σ and max multiple, computed by the engine
}

2.2 Listing rules — mathematics as the listing committee

A market is listable if and only if:

  1. Spread floor: Σ (pᵢ × payoutᵢ) ≤ 1 − base spread (1.25% at launch; see §4)
  2. Closed distribution: all outcomes and probabilities are fixed before the round; no in-round decisions affect expectation
  3. Exposure computability: the engine can derive σ and max payout from the definition

No committee, no negotiation. If the math passes, the market lists.

2.3 Two tracks

2.4 Truth sources

Every MarketDefinition declares its truth source on-chain. A position buyer sees, before staking, exactly what will decide the outcome and how it is verified. Three classes are supported:

(a) Verifiable randomness — synthetic distributions.

2.5 Randomness liveness & fallback

Verifiable randomness is a hard dependency, and the protocol treats its failure as a first-class scenario:

(b) Signed data feeds — parametric truth.

Markets on external indices — weather readings, flight arrival times, published prices, official statistics — settle against cryptographically signed data feeds (Chainlink data feeds and equivalent attested sources). The market definition pins the exact feed, the reading window, and the threshold; settlement is mechanical. No claims process exists because nothing is claimed: the index either printed past the threshold or it did not. Feed liveness follows the same discipline as VRF: no attested reading by the deadline → positions void and refund automatically.

(c) Bonded assertion — economic truth (roadmap).

For facts that no feed publishes, the protocol specifies an optimistic assertion game: an asserter posts the outcome with a bond; a challenge window follows; an unchallenged assertion settles the market; a challenged one escalates to a stake-weighted panel of oracle stakers whose minority is slashed, with further escalation to wider panels at higher stakes. Truth becomes the cheapest equilibrium. This class is specified for completeness and gated behind governance activation — markets may only reference it once the assertion module has been separately audited and parameterized.

A market's truth-source class is part of its on-chain identity. Frontends may filter to whichever classes fit their product and public; the vault and the fee waterfall are identical across all three.


3. Risk Vault

3.1 Structure

An ERC-4626 vault denominated in USDC. Depositors mint vault shares and become the market's risk seller pro rata. The vault pays winners, collects from losers, and accrues the net spread. No yield is promised. Depositors sell risk; realized results are whatever the distribution delivers.

Capacity is capped — by design. The vault is capped at $300M TVL at launch. The cap exists because vault size serves exactly one purpose: underwriting position limits — and at $300M the protocol already offers the deepest limits in the market. Capital beyond that would dilute LP returns without adding trader utility. The cap is a DAO parameter: governance may raise it (e.g. to $500M) when volume justifies deeper limits.

Entry into a full vault — the share market. While the vault is at cap, new capital cannot mint shares; it can only buy them. Vault shares are freely transferable ERC-4626 tokens: an existing LP may list shares at any price (e.g. 1.05× NAV), and an entrant who values the seat pays the premium. This creates a secondary market for vault capacity — the scarcer and more profitable the book, the more a seat costs — without ever expanding risk capacity or diluting the spread. Withdrawals (48h delay to prevent result-timing) free capacity, which reopens minting at NAV until the cap is reached again.

3.2 Exposure engine — three rules

Every position must satisfy all three, evaluated at placement time:

Rule 1 — Volatility cap (per position):

stake ≤ 0.2% × TVL ÷ σ_position

where σ_position is the standard deviation of the position's payout multiple.

Rule 2 — Max single payout (tail cap):

max_payout ≤ 1.0% × TVL

A fixed, simple, publicly known ceiling: no single round can remove more than 1% of the vault.

Rule 3 — Global net exposure:

Σ NetExposure(open rounds) ≤ 5% × TVL

where NetExposure(round) = max over outcomes [payouts to winners − stakes of losers]. Offsetting positions on the same round (e.g. red vs black) net against each other: the engine measures true exposure, not gross stakes. Shared global rounds (one spin, many traders) are therefore also a capacity multiplier.

Anomaly Breaker. Time-based stop-losses are statistically meaningless and are not used. Instead: if cumulative loss in a rolling window exceeds of expectation given realized volume, trading halts pending review. A 5σ event (~1 in 3.5M) is not bad luck; it is evidence of a broken assumption — a randomness fault, a payout bug, or an exploit. The breaker is a security control, not a risk-management control.

3.3 The Anchor Reserve — full limits from block one

The headline limits (§3.4) are the protocol's strongest marketing asset for the highest tier of traders — and they require $300M of verifiable capacity from day one, while a young book's LPs need returns computed on capital that is actually working. The vault therefore runs in two tranches under one pledge:

This is the classic insurance/reinsurance structure, on-chain: the active layer prices and absorbs routine risk; the reserve underwrites catastrophe and is paid a standby rate for it. Traders see one number — the deepest limits in the market; LPs see another — returns on working capital only.

3.4 Limits table (illustrative)

Position limits scale linearly with TVL. At $300M TVL:

Distribution archetype σ Max stake Max payout
Binary even-money (2×, p≈0.5) ~1.0 $600,000 $1.2M
Decision-path, curated (Track B) ~1.15 $520,000 ~$2.1M (edge case)
Uniform multiplier @ 5× ~2.2 $270,000 $1.35M
Uniform multiplier @ 10× ~3.0 $200,000 $2M
Single outcome @ 35.44× (p=1/37) ~5.9 $82,000 $2.9M
Long shot @ 100× ~10 $30,000 $3M (Rule 2)
Heavy tail @ 1,000× ~32 $3,000 $3M (Rule 2)
Extreme tail @ 10,000× ~100 $300 $3M (Rule 2)

For reference, the deepest centralized venues — physical or digital — cap even-money positions at roughly $300K–$500K, and single-outcome high-multiple positions rarely exceed $40K anywhere. At $300M TVL the protocol operates the deepest risk book in the market — publicly, programmatically, with no negotiation and no discretionary approval. Limits are a pure function of TVL: the market itself decides capacity.

3.5 Vault risk profile (illustrative, $300M TVL, ~$1.5–2B monthly volume)


4. Fee Architecture

4.1 Base + Markup

Trader price = Base Spread (protocol-fixed) + Brand Markup (brand-chosen)

Base Spread: 1.25% (governance-adjustable within [0.5%, 2%]), decomposed:

Component Share of volume Recipient
Protocol fee 0.15% RAIN buyback & burn (§6)
Base distribution 0.25% Referring frontend/affiliate
Trader rebates (pool) ~0.17% Volume-tiered rebates (§4.3)
Anchor Reserve standby 0.05% Reserve tranche (§3.3)
Vault spread (net) ~0.63% Risk Vault — residual claimant

Brand Markup: 0% to 2.5%, chosen per brand, disclosed on-chain and in the interface ("Protocol base 1.25% | Brand fee X%"). 100% of markup accrues to the brand. The ceiling protects the system-wide value proposition (worst-case total price ~3.75%, still below the effective pricing of legacy risk venues).

The market self-segments: API/automation aggregators at 0%, lean community brands at ~0.5%, full consumer brands (concierge service, incentives, events — funded from their own margin) at 1.5–2.5%.

4.2 Why the base is 1.25%

4.3 Rebates

Volume rebates return 10–25% of a trader's generated spread, tiered by rolling volume, accrued per round, claimable on-chain. Hard invariant: total rebates + incentives < spread, always. (This closes the bonus-farming vector: no combination of incentives may turn expected value positive for volume-cycling strategies.)

4.4 Decision games (curated track)

Decision-path products (Track B — distributions where in-round choices affect expectation) carry ~0.5% structural spread (to the vault) against optimal play. The protocol adds a notional fee of 0.10–0.15% per unit staked (initial stake and each in-round escalation) — certain revenue per action, rules untouched. Effective cost to an optimal participant ≈ 0.61–0.67%: the most transparent pricing available for this product class, and optimal (automated) strategies become high-frequency fee-paying volume rather than a threat.

4.5 Vault performance fee → burn

In addition to the volume-based protocol fee, the protocol charges a performance fee on realized vault profits, routed entirely to RAIN buyback & burn:

performance_fee = 10% × (net vault PnL above High-Water Mark)

4.6 Markup royalty → burn

Brands keep their markup as their core economics — but a brand charging 2% markup and a brand charging 0% should not contribute identically to the token sink. A deliberately light royalty applies:

markup_royalty = 10% × brand markup revenue

Token sinks, summarized: 0.15% of all volume + 10% of vault profit above HWM + 10% of brand markup. Volume, vault performance, and brand monetization each feed the burn — without ever making RAIN load-bearing for solvency.

4.7 Locked credits (deposit bonuses)

Brands may issue locked credits with wagering requirements, funded from their markup. The contract displays the full arithmetic to the trader (locked balance, remaining wagering volume, expected cost at current spread). Transparency of the deal is mandatory at the protocol layer.


5. Value Flow

Per unit of volume (illustrative, base-only flow at 1.25% base spread):

Volume (100)
│
├── Protocol fee 0.15 ──────────→ RAIN buyback & burn
├── Base distribution 0.25 ─────→ referring brand/affiliate
├── Trader rebates ~0.17 ───────→ volume-tiered, on-chain
├── Anchor Reserve standby 0.05 → reserve tranche (§3.3)
▼
Risk Vault ~0.63 (mix-dependent) — the residual claimant
└── 10% of profit above HWM ───→ RAIN burn (§4.5)

Plus Brand Markup (0–2.5%) flowing entirely to brands, outside the protocol waterfall.

Settlement is per round. There is no monthly reconciliation, no negative-carryover clause, no trust in reports: when the vault loses a round, there is nothing to distribute; when it earns, every claim pays instantly. All participants sit on the same boat at block granularity.

Recovery Gate. While the vault's cumulative PnL is below its High-Water Mark (i.e. LPs are under water), distribution payouts to brands and trader rebates are suspended and accrue to the vault until the drawdown is recovered. The 0.15% protocol fee and brand markup (the brand's own pricing) continue to flow. The party carrying the risk recovers first; the parties earning risk-free flow wait. This is enforced by contract, not by policy — and it is precisely what makes the per-round waterfall sustainable through drawdowns.

Affiliate/brand attribution is written on-chain at the wallet's first trade (default duration: 24 months, then evergreen at a reduced rate), making distribution revenue a composable, auditable — and potentially tradable — asset.


6. RAIN Token Integration

The protocol fee (0.15% of all volume) autonomously market-buys RAIN and burns it. The vault performance fee (10% of profits above HWM, §4.5) and the markup royalty (5% of brand markup, §4.6) are burned through the same autonomous mechanism.


7. Ecosystem Roles

Role Provides Receives Economics
Trader Volume The lowest generalized risk price on earth; on-chain rebates; trustless settlement; the world's highest limits Pays 1.25% + optional brand markup
Risk Vault LP Capital (sells risk) Residual spread flow No promises; expectation ≈ 0.5–0.6% of volume; drawdown profile per §3.4
Brand / Frontend Users, UX, marketing, service 0.25% base + full markup A $10K/mo-volume regular yields ~$175/mo at 1.5% markup — CAC pays back in weeks
Affiliate Referrals Share of base distribution, wallet-bound on-chain An annuity on referred flow, verifiable per block
Market creator New distributions (Track A) Creator fee: 10% of protocol fee on their market An open catalog that grows itself
RAIN holder Burn exposure to total volume §6

Go-to-market implication (from simulations): the top ~2% of traders generate roughly half of deposits and the bulk of volume (calibrated to public benchmarks of high-frequency retail risk venues: casual 78% at ~$12 avg position; regular 20% at ~$120; high-tier ~2% at ~$750; largest position-takers ~0.1% at ~$8K; top-tier globals on the order of 1 per 5,000 traders). The realistic scenario requires on the order of hundreds of high-value traders, not millions of casual users. The two magnets are engineered into the protocol: the lowest price and the deepest limits. Distribution economics favor organic, community-native channels and API-driven traders over paid acquisition; brands with markup can fund full-service, high-touch operations where justified.

Retention model (industry-calibrated). Acquisition follows the documented two-stage pattern of real-money platforms: ~40% of new sign-ups lapse within the first month; the surviving base is sticky, churning at ~5%/month (average established lifetime ~20 months). Organic referrals from the established base add ~4–5%/month of new sign-ups. Blended trader lifetime value converges to the industry-standard ~$2,500 as cohorts complete their lifecycle (realized over ~18–24 months, not at sign-up).

Launch economics (illustrative, validated in the live simulator). At a blended CAC of $700 per active trader (declining to ~$600 in year 2 and ~$500 from year 3 as the brand matures), a $1M launch budget seeds ~1,400 traders over a 90-day ramp. Growth thereafter is brand-funded: brands reinvest a declining share of their revenue into acquisition (≈50% in year 1 → 20% from year 4), bounded by an operational onboarding ceiling of ~25% base growth per month. An optional max-growth posture — brands reinvesting 90% of revenue and retaining 10% — roughly triples the two-year trader base at the cost of near-term brand profit; committed marketing accumulates in a war chest and deploys at the pace the onboarding ceiling allows. The cheaper channel remains indirect: recruiting brands and affiliates (who carry their own CAC for the 0.25% base + markup) scales the trader base at protocol cost near zero. One brand realistically serves ~600 traders (support, local marketing, payments), so the brand count grows naturally with the network.


8. Simulations

Assumptions: blended spread ~1.0–1.05%, waterfall per §5, protocol opex $150–250K/mo, initial vault $10M (founder), scaling with adoption.

Scenario A — Pessimistic: $10M monthly volume

Protocol $15K/mo; vault expectation $52K/mo with monthly σ larger than the mean (≈35% losing months — normal and survivable at this scale); distribution $17K/mo. Below protocol break-even; a proof-of-product phase with 6–12 months of acceptable burn, not a business.

Scenario B — Realistic: $50M monthly volume (~5,000 active traders, ~250 high-volume)

Protocol $75K/mo (≈ break-even); vault expectation $260K/mo (~15–16% annualized at volume/TVL 2.5, ~29% losing months, converging annually); distribution layer $675K/mo including markup (weighted avg markup ~1.1%); a mid-size consumer brand at $3M monthly volume earns ~$52K/mo.

Scenario C — Optimistic: $250M monthly volume (~25,000 active, ~1,250 high-volume)

Protocol $375K/mo → $4.5M/yr burned; vault expectation $1.3M/mo on $30M TVL (17% annualized, ~13% losing months); distribution $425K+/mo base plus markup. Protocol revenue at DeFi infrastructure multiples implies a $45–90M valuation for the extension alone — while total volume remains an order of magnitude below the largest centralized incumbents, indicating substantial headroom.

Scenario D — Deep-liquidity steady state: $300M TVL, $1.5–2B monthly volume

The maximum-capacity regime of §3.3–3.4. Vault expectation ~$9M/mo; protocol burn ~$2.25–3M/mo; daily risk profile as specified. This is the north-star scenario the limits flywheel targets:

More TVL → higher limits (linear, public) → largest traders arrive →
more volume → higher realized vault returns → more TVL

A unique property closes the loop: a large trader who believes the seller side always wins can become the seller — the same wallet can buy risk in the market and sell risk in the vault, each side deepening the other.


9. Competitive Position

Legacy centralized venue Crypto-native centralized venue RAIN Risk Markets
Price (headline) 2.7–8% 1% on a narrow product subset 1.25% on everything
Price (effective, high-volume) ~2.5–7% ~0.85–0.9% (discretionary rebates) ~0.75–0.85%, coded and public
Fairness Trust Provably fair outcomes Provably fair outcomes and payments
Solvency Trust Trust Collateralized pre-round, on-chain
Limits Negotiated, opaque ~$1M max payout Public function of TVL; $600K even-money at $300M
Rebates Discretionary Discretionary Tiered, on-chain, guaranteed
Distribution Closed contracts Closed affiliate program Permissionless Base+Markup; white-label without negotiation

Three claims no centralized incumbent can copy without destroying its own economics:

  1. "One low price on every product." Incumbents' cheap products are loss-leaders subsidized by expensive ones; here a single 1.25% base governs the catalog — below the incumbents' volume-weighted effective price.
  2. "We cannot hold your money — ever." Not a policy. An architecture.
  3. "The deepest risk book in the market, by design." A single operator carries tail risk on one balance sheet; an open vault distributes it across a capital market with a mathematically bounded profile.

10. Launch Plan & Parameters

V1 markets (Track A, synthetic truth): binary even-money, uniform multiplier (2×–100×), single-outcome 36×, multi-outcome ladders — the canonical closed distributions. V1.5: heavy-tail and extreme-tail archetypes; first parametric markets on signed data feeds (flight delay, weather indices). V2 (Track B, curated): decision-path distributions with per-action notional fee; bonded-assertion truth source subject to separate audit and governance activation.

Initial parameters:

Parameter Value Mutable by governance
Base spread 1.25% Within [0.5%, 2%]
Protocol fee 0.15% Within [0.1%, 0.25%]
Base distribution 0.25% Within [0.15%, 0.35%]
Markup ceiling 2.5% Within [1.5%, 4%]
Rule 1 constant k 0.2% Within [0.1%, 0.3%]
Rule 2 payout cap 1.0% TVL Fixed
Rule 3 exposure cap 5% TVL Within [3%, 8%]
Anomaly breaker Fixed
Withdrawal delay 48h Within [24h, 96h]

Bootstrap: founder-seeded vault ($10M, growing to target); staged TVL caps during audit maturation; double independent audits + public bug bounty before uncapped deposits; early-LP RAIN incentives from treasury (time-decaying).

Legal: published by the RAIN Foundation (Panama). The protocol layer performs no marketing, no end-user relationship, and no custody beyond contract escrow. What a market is called and to whom it is offered is a frontend decision, and each frontend carries the regulatory posture of its own product: a venue offering high-frequency synthetic risk positions, a distributor of parametric protection products, and a prediction-market interface face different regimes in different jurisdictions — distribution-layer compliance (licensing, geo-restrictions, responsible-use tooling) is the responsibility of each brand, and the Foundation's official frontend applies its own geo-policy. This paper is a technical specification, not an offer of securities, insurance, investment advice, or a solicitation to trade.


Appendix A — Convergence thresholds (per §1.3)

Product e σ n for 95% seller certainty n for 99%
Even-money binary (1.5% spread) 0.015 ~1.0 ~12,100 ~24,100
Uniform 2× (0.99%) 0.0099 ~1.0 ~27,800 ~55,400
Decision-path, optimal play (0.65% eff.) 0.0065 ~1.15 ~85,000 ~170,000
Heavy tail (0.99%) 0.0099 ~8–10 ~10⁷ — (portfolio-level only)

High-σ products converge at the portfolio level, not the individual level — which is precisely why Rules 1–3 bound them tightly.

Appendix B — Glossary

Position — a stake on a published distribution. Spread — the price of risk embedded in a payout table. LP PnL — gross revenue accruing to risk sellers. Net LP PnL — after rebates and incentives. Volume rebate — programmatic, tiered fee return on traded volume. Locked credit — a programmatic incentive with disclosed release conditions. Netting — offsetting opposing positions on one round before measuring vault exposure.


RAIN Risk Markets — Protocol Extension Paper v0.95. Draft for internal review. Parameters marked mutable are subject to governance ratification. © RAIN Foundation.