RSU vest - difference between grant and vest price -(LOSS)

The market price of my 100 stocks was $200 per share at the time of GRANT, jan 1 2015

When the stock actually vested the stock price was $50 per share. So before taxes came in I had about 100*$50.

Can I claim a deduction for the loss in expected value from the time of GRANT vs time of vest?