"FANG names are especially vulnerable to selling, particularly Amazon and Netflix, because their outperformance last year makes them a terrific source of funds for troubled hedge funds that need to sell their winners in order to raise money," the "Mad Money" host said.
That means the hedge fund liquidations are only temporary. In the long term, Lang believes that FANG is simply facing a pullback and on a longer-term uptrend.
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In fact, Facebook's monthly chart barely even shows a decline. The stock remained above its 20- and 30-month moving averages.
The chaikin money flow oscillator is an indicator that technicians use to measure how much buying or selling pressure there is on a stock. Facebook's money flow oscillator showed it is still in positive territory, which Lang interpreted as meaning there isn't much to worry about it in the long term.
As for the short-term perspective, there could be a rocky road ahead for some members of the FANG group. Facebook and Google both had decent prospects.
However, Amazon's chart was very problematic. Lang said the chart is clearly broken and didn't find much to like. The only good news is that Lang found signs that the pain could be coming to an end for Amazon.
As for Netflix, the stock was so oversold that Lang thinks it could be due for a bounce. He saw a floor of support for it at $80, down about $5 from its current price. Lang also believes that the recent downtrend could be coming to an end.
Ultimately, the charts revealed to Lang that in the long term, Facebook, Amazon, Netflix and Alphabet could be headed higher.
"Which means once this marketwide sell-off ends, FANG can get its groove back," Cramer said. (Tweet This)