Negative spreads and crossed quotes
Posted: Fri Oct 30, 2026 11:22 am
Negative spreads and crossed quotes
Occasionally the bid is higher than the ask. A negative spread. On a live platform, it looks like a bug, and in a way it is.
It happens when quotes from different providers are aggregated without proper handling, or when the feed lags on one side. For a few milliseconds, the best bid from one provider sits above the best offer from another.
In theory, this is an arbitrage opportunity: buy at the lower ask, sell at the higher bid. In practice, it disappears before any retail order can reach the server. Brokers that offer such prices usually reject the trades, or fill them at a corrected price, or in rare cases honour them and later cancel.
Platforms and brokers differ in how they handle it. Some correct the quote at the display level. Others let it through, which produces strange candles and sometimes triggers stops.
Spotting a negative spread in the log signals that the feed has quirks. A pattern of them around news suggests aggregation trouble.
A record of such events is useful if a dispute arises. Screenshots with timestamps are better than recollection.
Has a negative spread ever appeared on the platform, and what happened to orders placed at that moment?
Occasionally the bid is higher than the ask. A negative spread. On a live platform, it looks like a bug, and in a way it is.
It happens when quotes from different providers are aggregated without proper handling, or when the feed lags on one side. For a few milliseconds, the best bid from one provider sits above the best offer from another.
In theory, this is an arbitrage opportunity: buy at the lower ask, sell at the higher bid. In practice, it disappears before any retail order can reach the server. Brokers that offer such prices usually reject the trades, or fill them at a corrected price, or in rare cases honour them and later cancel.
Platforms and brokers differ in how they handle it. Some correct the quote at the display level. Others let it through, which produces strange candles and sometimes triggers stops.
Spotting a negative spread in the log signals that the feed has quirks. A pattern of them around news suggests aggregation trouble.
A record of such events is useful if a dispute arises. Screenshots with timestamps are better than recollection.
Has a negative spread ever appeared on the platform, and what happened to orders placed at that moment?