Well to be more specific, why do dealers/brokers hold inventory in stocks for longer than normal periods of time (for example the dealer/broker might hold inventory overnight or over the weekend). This topic gives an idea as to why a broker would want to hold inventory: How does a dealer (or market maker) earn the bid-ask spread on a stock?
But I'm kinda wondering if there any reasons as to why a dealer or broker would want to hold inventory in stocks for long periods of time. I think getting dividend payments is one example as to why they would want to, but are there any other reasons?