Sunrun Inc. (NASDAQ: RUN), a leading provider of residential solar and energy services, saw its shares surge by 11.77% in Tuesday's pre-market trading session. The dramatic uptick comes on the heels of news regarding insider buying at the company, which has sparked significant investor interest.

According to a recent SEC filing, Edward Harris Fenster, a Director at Sunrun Inc., reported an acquisition of common shares of the company. While the exact details of the transaction, including the number of shares purchased and the price paid, were not immediately disclosed, the mere fact of a director buying stock has been interpreted as a bullish signal by the market.

Insider transactions, particularly purchases, are closely monitored by investors as they can provide valuable insights into a company's prospects. When company insiders, such as directors or executives, invest their own money in the company's stock, it's often seen as a vote of confidence in the firm's future performance. This insider buying at Sunrun has clearly resonated with investors, leading to the substantial pre-market rally and setting a positive tone for the day's trading session.