What happened

One of the hottest segments on the stock market now is electric vehicles (EVs). This week got off to a roaring start for two stock connected to them -- Workhorse Group (NASDAQ:WKHS) and Tortoise Acquisition (NYSE:SHLL), which accelerated almost 47% and 30% higher, respectively, on Monday.

So what

Workhorse, which specializes in electric delivery vans and drones, got a big shot of legitimacy on Monday when it was added to the Russell 3000 Index. Although being included on a storied equities index doesn't change the nature of a company's business, it confers legitimacy and makes a stock a candidate for some of the many index funds popular with investors these days.

A Workhorse EV.

Image source: Workhorse Group.

Tortoise Acquisition isn't technically an EV manufacturer... or a manufacturer of any kind. Rather, it's a special purpose acquisition company (SPAC) formed to acquire and absorb another business. Tortoise's target is Hyliion, a company that specializes in powertrains for electric and hybrid-electric heavy trucks.

Tortoise had no news of its own to report, but the optimism that greeted Workhorse's Russell 3000 news is spilling over. EVs are a growing part of the transportation landscape, and both companies are busy carving out their niches.

Now what

A white-hot sector always cools down. The excitement over EVs will subside, despite the big potential the segment holds for the future. Investors will expect growth and -- at some point -- profitability, and just now the EV industry is too young and capital-intensive to achieve either consistently.