It's been a few weeks since I tried but last time I did, you could place a sell order but not a buy order. It's purely a TD Ameritrade thing. It was my understanding after talking with everyone at TDA & MNGG, once the 10 day trading volume reaches 50 million again the buy restriction will be lifted. Now things could have changed but that's my current understanding. No other U.S. broker has any issue at all, buy or sell.