court case, page-48

ProPunter - for the benefit of the ignorant (like me), how long do short sellers have before having to 'cover' their short positions?
I understand the concept of short selling to be 'selling' shares you don't yet own as effectively a punt that when you have to eventually make good (cover) the price will be lower than when you 'sold'.. But I would have thought this would be a fixed time frame (i.e. 3 days to settle). My suspicion is short sellers continue to take more short positions in an effort to create downward momentum in a stock, and also allow them to cover earlier short positions - but eventually the stock will get to a price where it is sufficiently undervalued that the market will drive it back up?