A trader on the prediction market platform Polymarket has generated a profit of $233,928.97 by capitalizing on short-term price movements in XRP and Bitcoin, particularly during periods of low weekend liquidity. The trader, using the username a4385 (also referenced as PredictTrader), joined the platform in January 2025 and has since executed 38 successful predictions.
The strategy centered on the "XRP Up or Down" and "Bitcoin Up or Down" markets on Polymarket. One notable trade involved a bet of $36,799.89 on XRP, which returned $77,018.80—a 109.29% profit. Profits from Bitcoin markets were also substantial, at $48,275.25 and $63,980.13. The trader's total position value is reported at $6,781.32, with a single largest win of $40,218.91.
The key to success was exploiting thin liquidity, especially on weekends when automated market maker (AMM) bots on Polymarket can create amplified price swings. The trader placed rapid-fire trades within 15 to 30-minute windows to capture these micro-fluctuations.
A detailed account from one event describes the trader aggressively buying "UP" shares in an XRP contract on a Saturday. As the UP share price rose due to buying pressure—even while the XRP spot price fell—Polymarket's bots sold more shares. The trader accumulated approximately 77,000 UP shares at an average cost of 48 cents. Two minutes before the market closed, a Binance wallet, allegedly linked to the trader, executed a large purchase of $1 million worth of XRP, causing a roughly 0.5% price spike. This small increase settled the Polymarket contract in favor of the "UP" outcome, allowing the trader to cash out shares at $1 each for a significant profit. The XRP purchased on Binance was subsequently sold, returning the spot price to its prior level.
This series of events has sparked discussions about potential market manipulation and highlights the need for more sophisticated algorithms and clearer regulatory frameworks within prediction markets.
