Chris Sacca, the Lowercase Capital founder known for sporting cowboy shirts and appearing on ABC's Shark Tank, is retiring from startup investing. Sacca will no longer make deals with the sharks and Lowercase will not accept any additional money, he announced on Wednesday.

"It's hard to leave all this behind right when things are going so well," Sacca wrote on Lowercase's website. "I'm good at what I do and still getting improving (sic) as I learn from mentors, founders, partners, friends, family, strangers, my own investors, and the experience itself."

The former Google lawyer was one of the earliest investors in companies like Twitter and Uber. In his blog post, Sacca said he and his wife Crystal found a note he wrote at 20 that laid out his career goals for the next two decades. One such goal was having a "high risk, high reward" job, and then walking away from it by age 40 to do something he really cares about. Sacca turns 42 on May 12.

While Sacca has been vocal about his political views, he doesn't have any plans to run for office. Instead, that time will be spent on television appearances, launching a podcast, and raising three kids with Crystal. This decision also means he won't return as a guest judge on Shark Tank.

"The love I got from you guys during my two seasons on the show was incredible. It choked me up at times," Sacca wrote. "Turned out, the Twitter feedback was teeming with high-fives, my episodes' ratings were strong, the critics loved it, I invested in some fantastic companies, and most importantly, I had so damn much fun."

Sacca added that Mark Cuban, the bull shark in the tank, was the "most bummed out" to find out he won't return. Sacca wrote that they are "competitive good friends," but that everyone was generous and warm with him.

As for his venture capital fund, Lowercase partner Matt Mazzeo will manage the existing portfolios and sit on several related boards. A request for comment was not immediately returned by Lowercase.