Piper on Monday raised its price target on Tesla to $368 from $223, representing more than 20 percent upside from Friday's close.
The move amounts to the highest price target on Wall Street from a major research firm, according to FactSet. Dougherty & Co., a smaller firm, has had a $500 price target on Tesla since October.
Piper also upgraded Tesla's stock to overweight from neutral, noting the company's products "have a captivating impact on consumers and shareholders alike; this advantage will be difficult to replicate."
"In the minds of its customers, employees, and shareholders, Tesla isn't just another company," they added.
Tesla shares year to date
Source: FactSet
The research firm, however, pointed out investors should brace themselves for a "bumpy ride." "But even with all the risks, we think growth investors can't afford to ignore this stock."
Tesla shares hit an all-time high of $304.88 per share on Wednesday. The stock is also up 41.6 percent in 2017.
Founder Elon Musk teased short sellers on Twitter this month as the stock surged in market value past established carmaker Ford. Piper believes Tesla at this point may be bear-proof:
"We sympathize with bears — but their (arguably rational) arguments probably won't matter. In many ways, TSLA seems to play by its own rules. The company burns through cash at a rate that better-established companies would likely be crucified for ... Tesla's production timelines are unreasonably fast. ... Yet, because of its superior products, loyal shareholders, and inspiring mission, TSLA remains unscathed."