Quote from bellman:
For any American stock exchange (NYSE, AMEX or Nasdaq), can equities trading below $1 be traded at fractions of a penny and stocks trading > $1 must trade in penny increments?
Quote from tommintj:
Stock Bids and offers above $1 and priced in subpenny increments cannot be accepted from retail customers due to SEC's Rule 612. Trading can be done by a broker/dealer in subpenny increments.
See http://defendtrading.com for more info