It's crunch time for the specialist firms that once were the powerhouses that drove trading on the New York Stock Exchange ( NYX). The Big Board is putting the finishing touches on its so-called hybrid market, which combines electronic trading with old-fashioned floor trading. Beginning today, 3,600 stocks and other securities listed on the NYSE can now be traded either electronically or through the aid of a specialist -- a floor-based trader. That's great news for investors because the hybrid market will no doubt lead to lower trading-related costs. But the full rollout of the hybrid market, which already is crimping profit margins for the specialists, could push Big Board trading firms such as LaBranche ( LAB) and Van der Moolen ( VDM) over the edge. On Tuesday, Dutch-based Van der Moolen said it was laying off 30% of the employees at its U.S. specialist division. The firm blamed the job cuts on the hybrid market's cutting into its market share. LaBranche earlier announced its own round of equally deep job cuts. Other firms such as Bank of America ( BAC) and Lehman ( LEH) have also made severe cuts in their specialist businesses. And things are likely to only get worse for the specialists now that the hybrid market is fast making in-person market makers obsolete. The final leg of the NYSE's hybrid platform intensifies the need for a stand-alone specialist firm like LaBranche to either figure out another business model or toss in the towel.