Accumulation refers to the gradual building up of a basket of shares without rapidly driving up the price. This is a term from technical analysis and describes a period that often precedes a sharp rise in the stock price. During the accumulation period, there is usually significant transaction volume. The opposite of accumulation is "distribution," where shares are actually sold gradually.

This term is specifically relevant in the context of market analysis, where investor behavior and stock price movements are closely monitored to predict future trends.