There is no financial advantage to exercising early because you expect a price increase. The only reason to exercise early is to sell (or possibly cover, see below). <br /> <br /> nwbo warrants are deep in the money. If they still have time to expiration, warrant value rises in tandem with any rise in stock price. <br /> <br /> Consider a warrant holder who is hedged by shorting. If that short is recalled, and it is not possible to find borrow elsewhere, then they might prefer to exercise warrants and cover. <br /> <br /> Also consider the similar case of what happened in late June to early July with warrant expirations. Shares Outstanding rose. Short Interest dropped. Stock price was fairly stable on ordinary volume. The likely explanation is that the warrant holders exercised, then delivered those shares to cover rather than selling in the market.