An already-sad market for media stocks became even drearier as Wall Street — fearful of a slowdown in the global economy — followed two days of declines with its biggest single-day downturn since early 2014. The Standard & Poor’s 500 and Dow Jones Industrial Average each fell about 2.1% while the Dow Jones U.S. Media Index dropped 3.9%. The S&P has now lost all of ground it gained in 2015.

NetFlix Reports Quarterly EarningsEvery company we monitor declined today. That notably includes Netflix, whose prospects depend on the success of its ambitious global expansion efforts. Its shares fell  7.8%, equal to a $4.4 billion drop in its market value to $52 billion.

Those touching 52-week lows include Twitter, CBS, Discovery, Carmike Cinemas, TiVo, RealD, Alibaba, and Barnes & Noble.

Broadly speaking, investors fear that economies are slowing around the world — led, or at least exacerbated, by weaker than expected performance in China, which recently devalued its currency. That contributed to concerns about an oversupply of oil, as the price of U.S. crude fell below $40 a barrel for the first time since 2009. On top of that, many wonder whether the Federal Reserve will raise interest rates, something it hasn’t done for about a decade.

Big Media companies had an additional burden today after an influential Wall Street analyst downgraded the industry amid growing concerns about cord cutting. Viacom shares fell 6.3% followed by Disney (-6.1%), CBS (-5.1%), Discovery (-5.1%), Time Warner (-5.0%), Fox (-4.2%), Sony (-4.2%), and Comcast (-2.6%).

Others with steep drops include Sinclair (-7.6%), Imax (-6.3%), Twitter (-5.8%), DreamWorks Animation (-5.4%), Carmike (-4.8%), AMC Networks (-4.5%), Dish Network (-4.3%), Regal Entertainment (-4.2%), Madison Square Garden (-4.1%), Lionsgate (-4.0%), AMC Entertainment (-3.9%), and RealD (-3.9%).