Key TakeawaysRobinhood shares plunged Thursday after the online brokerage company missed Wall Street’s quarterly revenue expectations due to a customer promotion program.The stock broke out above the top trendline of an ascending triangle earlier this month, though the recent bullish price momentum came to a halt after the company's third-quarter results.Investors should watch important support levels on Robinhood's chart around $24, $22, and $20.50.The measuring principle, which calculates the depth of an ...