Tesla (TSLA 6.83%) stock is on the move again today. After jumping 6% yesterday, Tesla have shares bounced another 5.8% Friday as of 11:53 a.m. ET. The recent surge has Tesla stock trading at its highest level since February.

Investors might be reacting to news from the company earlier this week regarding its energy business.

Image source: Tesla.

Tesla’s growth engine isn’t currently from EVs

Earlier this week, Tesla held an event in Las Vegas to introduce new products from its energy storage business, and it included a bit of a surprise. Its next-generation Megapack 3 energy storage system was introduced as expected. But the company also unveiled the new Megablock.

The Megablock combines several Megapacks along with electrical power system components. It’s a pre-engineered system that Tesla says will lower costs and installation times for large-scale energy projects. Mike Snyder, Tesla’s VP of energy and charging, also said that Tesla plans to build Megapack 3 in Houston starting late next year.

Tesla’s energy storage business is thriving even as its electric vehicle (EV) sales are slumping. Energy generation and storage revenue jumped 18% year over year to $5.5 billion in the first half of 2025. At the same time, automotive revenue declined by 18%.

Tesla shares have rallied 15% over the last month. Much of that happened this week after the Las Vegas presentation, which was also streamed live on Tesla’s X social media account. Investors had mostly been focusing on the potential of Tesla’s robotaxi when it is launched in volume.

In the meantime, the energy business is growing into a more meaningful part of Tesla’s revenue stream. That’s enough to move the stock much higher this week.