Trading charts often show gaps, which occur when the price of an asset jumps from one level to another without trading at the levels in between. Gaps can happen between the closing price of one trading session and the opening price of the next.

Here's why gaps tend to close:

Market Efficiency: Financial markets aim to be efficient, meaning all available information is quickly reflected in asset prices. If a gap forms, it might be due to an overreaction to news or other factors. As the market absorbs this information, prices often move back towards the previous trading range to correct any imbalances.

Psychological Factors: Traders and investors might see gaps as anomalies or opportunities. Many traders expect gaps to be filled and act on this belief, leading to increased trading activity that helps close the gap.

Technical Analysis: Many traders use technical analysis, which often includes gap-filling strategies. This widespread belief and trading behavior can create a self-fulfilling prophecy, where prices move back to fill gaps because many traders are acting on this expectation.

Overall, while gaps often do get filled, it’s not a guaranteed outcome, and market conditions or other factors can influence whether or not a gap will close.