Although US stocks are drifting sideways, New York has seen the emergence of several aggressive investment and research houses. Big firms may have slashed their workforces amid slumping revenue but boutiques are growing. ThinkEquity, which focuses on the 'knowledge economy' - covering everything from the media to education - had $15m (£10.5m) in revenue in its first year and expects to double that in its second. 'You have to be determined and patient,' said Paul Deninger, managing director at Broadview, a small tech mergers and acquisitions specialist.