- At around 7:00AM on its ask chart, ask price ranges between 103.580 to 103.650.
- At around the same time on its bid chart, bid price goes up as high as 103.740.
I understand that this is because of (1) a sudden change of bid-ask spread (Usually ask > bid in a stable market, but suddenly at 7.00AM., bid is way higher than ask.), and (2) the sudden change occurs under high volatility or low liquidity.
But I don't quite understand how (2) leads to (1), and why can't brokers keep their spread same under (2)?
Could someone shed light on the mechanism?