NYFIX acquired Javelin Technologies for $11 million in cash and close to $44 million in NYFIX stock. Both companies develop the FIX messaging protocol for electronic trading of securities. The acquisition increases NYFIXs market share of broker-dealers and buy-side institutions, said Jennifer Plaia, vice president. The deal closed March 31. Javelin clients include the American Stock Exchange, Tradescape, Fidelity Management & Research and Instinet.