QuantumScape shares extended seven straight sessions of gains, as the stock advanced another 16.5% in morning trading on Thursday.

The EV battery maker nearly doubled this month. The stock has gained more than 150% so far this year, compared to a 6.7% rise in the broader S&P 500 Index.

Investors continued to focus on recent technical breakthroughs and show renewed optimism about the company's future in solid-state battery technology for electric vehicles.

Last month, QuantumScape announced that it had successfully integrated its new Cobra separator process into baseline production ahead of schedule. The process is a significant improvement over its previous system, offering a 25-fold increase in manufacturing speed and requiring much less equipment footprint.

"QuantumScape's Cobra process is a major manufacturing win, but the recent stock rally has priced in a full victory lap, which is premature," pointed out a Seeking Alpha analysis.

Turning to the Wall Street community, one analyst gave QS a Strong Buy rating. Five analysts have given the stock a Hold recommendation, while three recommended Sell or lower.