#ethereum

Crypto Trading Systems Bug Report

EVM bot transactions fail with nonce too low and replacement transaction underpriced

Ryan Pham · Jun 3, 2026 · 6 min read

Our settlement bot sends several transactions per minute from one address. After we parallelised it, sends failed with nonce too low and replacement transaction underpriced, and some transactions sat stuck for hours. A single nonce manager per address and correct fee bumping fixed it.

Crypto Trading Systems Bug Report

DEX swaps reverting with Too little received: stale quotes, slippage bounds and deadlines

Ryan Pham · May 13, 2026 · 6 min read

Our treasury rebalancing service swapped on a DEX and about a quarter of swaps reverted on volatile days with Too little received, wasting gas. Quotes were computed seconds before submission and transactions waited in the mempool. Fresh quotes, simulation and a deadline fixed it without loosening slippage.