They now have to exercise by April 10, but if they do exercise, they hold restricted securities until June 7, which is almost two months.  In a volatile stock, in a volatile market, that is a virtual epoch, and, accordingly, not at all an insignificant risk.

 Surely, if they intend to exercise, they will wait until the last day (there is no benefit to exercising early, and there could be great benefit to waiting till the last day, eg, the stock could plunge the day before to a price where it would make no sense to exercise).

 Soooooo, what to do?  I think some may well sell their unrestricted stock at some point between now and April 10, in order to lock in some profit on the warrants, and eliminate the risk of just exercising without having earlier or simultaneously sold an equal number of unrestricted shares (or some smaller number, of course, depending on risk tolerance).  And if they think along those lines, why not sell sooner, rather than later?  The bird was in the hand as of just before closing today, that would have been the safest time to sell and lock the profit.  Once trading closed today, all bets are off, the stock could soar, plummet, or stagnate (this last is the least likely!), and could certainly soar or plummet at any moment.  (If these warrant holders don't have any more unrestricted stock, they can merely sell some short.)

 Put yourself in a warrant holder's shoes:  it's 3:30 on April 10, and NOT stock is trading for $5.70.  Do you exercise, do you pass, do you sell unrestricted stock and then exercise?  Do you regret not selling on March 12 for $6.50?

And if selling any stock was not something you cared to do, at what price do you exercise? What's the negative value of that almost two month restriction?