Tetra Tech (NASDAQ:TTEK – Get Free Report) was downgraded by investment analysts at Wall Street Zen from a “buy” rating to a “hold” rating in a research report issued to clients and investors on Friday. Finally, Weiss Ratings reiterated a “hold (c)” rating on shares of Tetra Tech in a research report on Saturday, September 27th. Get Tetra Tech alerts:Get Our Latest Research Report on Tetra TechTetra Tech Price PerformanceNASDAQ:TTEK opened at $33.74 on Friday. Tetra Tech has a 12 month low of $27.27 and a 12 month high of $51.20. Featured StoriesReceive News & Ratings for Tetra Tech Daily - Enter your email address below to receive a concise daily summary of the latest news and analysts' ratings for Tetra Tech and related companies with MarketBeat.com's FREE daily email newsletter.