Reasons...The recent sale by a director could have happened for many reasons. As has been suggested they may think prospects are poor and want to sell at a profit.
It may also be that they expected prospects to be good, the price to rise, and they wanted that gain to be realized elsewhere, like a family trust, holding company, spouse or other entity. To facilitate that a trade would occur, and because the exercise price was well below the market at the time, it would attract tax. It would make sense therefore to take some cash out to provide for taxes, and to move the block in 2 tranches.
Since there have been no further sales, and since the trade was not done at market in small pieces to random buyers, it is more likely that estate and tax planning was the reaon for the trade.
As the options were set to expire quickly, and with the blackout period approaching, there was no choice in the timing. It is also likely that as financing for both Volta and the 5 year plan are imminent directors could be blacked out for a considerable period of time.
Regardless of what it was, it has not dampened enthusiasm for the shares.A single director doing some tax planning was no reason for excitement.
In the recent earnings call Dr SN indicated the credit facility terms were going to be at rates consistent with what they are paying now on the small debt amount they have. The rates suggested on this board of up to 13% seem higher than I would expect Dr SN to accept. He has been frugal and cautious all along, I do not expect him to agree to onerous terms.
Best of luck