Crypto Newbie / Simulators / DeFi Insurance Pool
Decentralized Insurance Pool Simulator (Nexus Mutual Style)
Nexus Mutual pioneered decentralized insurance for DeFi — members pool capital and sell cover for smart contract bugs, exchange hacks, and protocol exploits. This simulator quotes a cover policy based on amount + duration + risk class, shows pool capacity limits, and projects yields for capital providers. It works for any mutual-style insurance protocol (Nexus, Bridge Mutual, InsurAce).
Insurance pool state
Your policy
Your quote
Premium
$863
% of cover: 1.73% · Annualised rate: 7.00%
✓ Available
Max available: $100.00M
Pool health
Capital utilization
60.0%
⚠ Moderate (50-80% utilized)
Capital provider economics
Annual premium income
$12.00M
Expected payouts
$4.50M
Net annual return
$7.50M
Net APY for capital providers
7.50%
How premiums are priced — risk class × amount × time
Premium formula: cover_amount × risk_rate × (days / 365). Risk rates: low (2.5%/yr) for battle-tested protocols like Aave V3 / Uniswap V3 core. Medium (7%) for newer audited protocols (Pendle, EigenLayer). High (15%) for bleeding-edge or those with attack history. Very high (30%) for bridges, new chains, unaudited contracts. So $50k cover on a medium-risk protocol for 90 days costs $50,000 × 0.07 × (90/365) = $863. The pool collects this; if no claim, capital providers keep it as yield.
Pool capacity — why some cover requests fail
Insurance pools can't underwrite unlimited cover — they're limited by their capital reserves. Maximum cover capacity = total_capital / MCR_ratio. With MCR of 40% (Nexus standard), a $100M pool can underwrite $250M in total cover. If existing cover already totals $230M, new applications can buy at most $20M more before the pool refuses. This is the simulator's 'remaining capacity' display.
Capital provider economics — net yield depends on claim rate
Capital providers earn the premium spread minus expected payouts. If pool sells $150M in cover at average 8%/yr premium, that's $12M/yr income. If expected claim rate is 3% of cover (mostly small claims, occasional large), expected payouts = $4.5M. Net = $7.5M income on $100M capital = 7.5% net APY. But claim rates are volatile — one bad year (10% claim rate) and providers lose money. Most providers diversify across multiple insurance pools.
Why decentralized insurance is small despite obvious demand
DeFi has $200B+ in TVL. If just 5% was insured, that's $10B in cover demand. Nexus Mutual has ~$50M in cover outstanding. Why so small? (1) Setting accurate premiums is HARD without actuarial data. (2) Member-voted claims process has anti-payout bias (members want to keep money in pool). (3) Adverse selection — people who buy insurance know more about their risk than the pool. (4) Most DeFi users self-insure by diversifying across multiple protocols rather than buying explicit cover. (5) Cover doesn't include 'I made a bad investment decision' — only specific named events. Most retail losses are not covered events.
Frequently asked questions
+Does Nexus Mutual actually pay claims?
Yes, with caveats. Nexus has paid ~$5M in claims over its history (notably $2.4M after the bZx exploit in February 2020, and several smaller payouts). But many claims have been denied — Nexus members vote on claim validity, and votes lean toward denial. Major denied claims include the Bancor hack and several smart contract bugs that members judged 'should have been known risks.' Read the specific cover terms before buying.
+Why does buying cover for low-risk protocols cost so little?
Low risk = low premium. Aave V3 has had no successful exploit in 3+ years, $10B+ TVL, audited by 5+ firms. The 2.5% annual rate reflects that low actuarial risk. But low risk doesn't mean zero — a black swan event (e.g., critical Solidity compiler bug discovered) could still cause losses across the entire DeFi stack. Cover protects against that scenario, even if the protocol-specific risk is low.
+Can I provide capital to multiple insurance pools to diversify?
Yes, and you should if providing significant capital. Different protocols have different risk profiles — splitting capital across Nexus + Bridge Mutual + InsurAce reduces correlation. Stake larger amounts on lower-risk pools (Nexus has the longest track record), smaller amounts on newer pools for higher yields. Returns from $100k+ across 3 pools typically run 8-15% net APY in average claim years.
+What's the relationship between MCR and pool health?
MCR (Minimum Capital Ratio) is the minimum capital the pool must hold per dollar of cover sold. If MCR = 40%, pool must hold $0.40 per $1.00 in cover (i.e., can underwrite 2.5x its capital). When utilization approaches 100%, the pool refuses new policies — it's 'full.' Healthy pools maintain 30-60% utilization; stressed pools (>80%) signal either too much demand or capital flight. The simulator shows pool health based on this.
+Are there alternatives to Nexus Mutual?
Yes: (1) Bridge Mutual — focuses on portfolio protection and stablecoin de-peg coverage. (2) InsurAce — multi-chain DeFi insurance with auto-quote API. (3) Sherlock — peer-to-peer protocol audit insurance with bounty integration. (4) Unslashed Finance — insurance with collateral on Ethereum. (5) Native protocol-level safety modules: Aave has a $500M safety module (LDO + AAVE tokens); MakerDAO has a buffer fund. For institutional-grade cover, also consider real-world insurers expanding into crypto (e.g., Marsh, AON syndicates).