Hack history / Monthly reports / 2021-05
Crypto hacks and thefts, May 2021
Thefts are hacks, exploits, phishing, scams and rug pulls, in dollars at the time. A single source for $500M or more waits for a second source before it counts.
Taken
$385.8M
26 thefts
vs the month before
−85%
−85% ($2.61B)
vs a year earlier
2572×
2572× ($150K)
Largest thefts
Venus Protocol 18 · Spot Price Manipulation$100MBunny 19 · Spot Price Manipulation$45MDeFi100 23 · Rug Pull$32MSpartan 01 · Incorrect Share Accounting$30MxToken 13 · Oracle Attack$25M$24.5 million emptied from xToken platform 12 · Hack or exploit$24.5MXtoken 12 · Spot Price Manipulation$24MBearnFi 17 · Withdrawal Logic Flaw$18MRari Capital 08 · Arbitrary External Call$14Mflash.sx / vaults.sx 14 · Reentrancy$13M
How attackers got in
Price, oracle and governance 6$194M
Smart contract bug 15$125.6M
Insiders: rug pulls, frauds, collapses 1$32M
Other 2$24.5M
Keys, accounts and infrastructure 2$9.7M
By chain
BNB Chain 16$282.6M
Ethereum 7$91M
not stated 5$27.2M
EOS 1$13M
By target
DeFi protocol 16$290.6M
not stated 10$95.2M
Collapses and frauds, counted apart
1 cases, $0.
Cite this page
SwanBluechip, "Crypto hacks and thefts, May 2021", Crypto hack history, https://swan-hack-tracker.pages.dev/history/m/2021-05/ (data as of 2026-10-31).