Tesla Inc 's stock was on fire for most of 2017, but after peaking at $386.99 in June, the stock has since lost more than $70 per share and is now stuck in a "technical bear market," according to Oppenheimer's Ari Wald. Wald, head of Oppenheimer's technical analysis, explained during a CNBC "Trading Nation" segment that Tesla's stock is now down more than 20 percent from its highs but there could be further pain for bulls ahead. Specifically, Tesla's stock is hovering within striking distance of the $290–$300 range, which represents a former breakout level but will now act as a support level.Read more