M&A takeovers are a big problem for warrantholders.Many who buy warrants do so for their long expiry date but, generally, these warrants are way-out-of-the-money—the hope is that the price will rally significantly over the years before the warrants expire. So, if a company is bought out, the buyout price may be below the strike price, rendering the warrant worthless. Such a scenario unfolded in the recent buyout of Gold Wheaton, a gold company, by Franco-Nevada
https://can-turtles-fly.blogspot.com/2010/12/newbie-thoughts-risk-with-warrants-from.html