Tesla shares rose to more than 10% on Wednesday. CEO Elon Musk promised investors to achieve positive cash flow in the following month and to start profitability in 2016. However, investors still have concern about its performance as it booked another loss in Q4 2015.

According to Reuters, Elon Musk and the company's new chief financial officer, Jason Wheeler, sought to assure investors on a conference call on Wednesday evening. Wheeler said a short comment, "Cash is king."

Tesla recruited Jason Wheeler from Google as new chief financial officer in November 2015. As a veteran in Google, Wheeler was VP of Finance in Google for 13 years. Tesla expected him to turn the company trait of loss into profitability, and the company is now determined to cut costs, hit production targets and stanch losses.

Jason Wheeler's experience will help Tesla to manage its cash reserves. As of December 31, the company's cash reserves has dropped to $1.2 billion from $1.9 billion a year, despite sale of shares. Some analysts have raised concern with Tesla's burning cash.

Fortune reported that the electric car maker has long enjoyed the status of Silicon Valley darling for its brash innovation in electric cars. Tesla and its technology advancement, such as over-the-air software upgrades have given a challenge to carmakers in Detroit, which is traditional place for American automakers.

Although CEO Elon Musk and his team are optimistic to bring the company's into the profit in 2016, but investors are still doubtful. Its nearly tripled fourth-quarter net loss have marked the 11th consecutive quarterly loss. The company reported a $320.4 million net loss in the fourth quarter nearly tripled to its last year's loss at $107.6 million.

However, the Palo Alto-based company is optimistic about its sales forecast in 2016, along with launching of its new product in 2017. This future outlook gives enough confidence to investors as its shares soared up to 14% in after-hours trading.

Elon Musk told Wall Street Journal, "I feel very good about things right now. The last several months have been quite excruciating."

Tesla planned to boost the production of Model X, its new crossover in 2016, after its weak sales and delivery in fourth quarter of 2015. The shareholders have noted this by pointing out that in the fourth quarter of 2015, from 17,478 cars delivered to customers, there were only 206 Model X cars.

Although Tesla shares rose to more than 10% on Wednesday, the company must work hard to gain profit in 2016 after its consecutive loss for more than three years. CEO Elon Musk has promised investors to achieve positive cash flow starting next month.