Commission-free stock trading at RoboMarkets is available only on R StocksTrader accounts with 1:1 leverage.
Other differences include:
Only BUY orders can be placed (Market, Limit, Stop).
Stop Out at 0%.
No financing fee.
No limit on maximum order volume.
Available instruments: only real US stocks (.nq or .ny suffix in tickers).
To register your Members Area with an R StocksTrader-account, follow the link.