I've been following the amount of shares available for short at Interactive Brokers through this link: View Shortable Stocks The amount oscillates rather frequently between 400k and 100k shares. This is most probably due to IB system's accuracy. But could it be something else? I've seen the value go under 100k only twice (it got to about 50k shares after the day after the stationary storage event and this morning after ER). What is this about? Is someone using those shares to manipulate the market? 300k shares is a lot of money...how can it oscillate so frequently during the day? Big players must be involved. Any ideas?