Trading penny stocks differ from one broker to the next. TD Ameritrade has some great features, but I did run into some trouble trading certain penny stocks. Sometimes TDA simply restricts the trading of some stocks, but some other broker have restrictions also.
I use Scottrade and it seems to be OK for the most part but they too have occasional restrictions.
There are some brokers out there that have NO restrictions on penny stocks. I can't think of one right now but I'm sure you can find them with Google or maybe someone here can weigh in and point to such a broker.
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