By Bret Kenwell Roku stock will be in the spotlight when it reports earnings. Here are the key levels to know now. Investors don’t need much more evidence than they’ve already got that we’re in a bear market in growth stocks. And Roku (ROKU) – Get Roku, Inc. Class A Report shares have been caught up in the pressure. The streaming-equipment major’s shares are currently down about 70% from their record just a few quarters ago. Even today, the stock is down close to 7% as investors express concern about how the stock will react to tonight’s earnings report. It’s been a brutal ride the past few mo…