Kartik Joshi, a partner at hedge fund Tourbillon Capital, has left.

The New York firm has struggled this year.

Tourbillon's flagship fund is down -11.6% this year through November.

Kartik Joshi, a partner at New York-based Tourbillon Capital, has left the fund, people with knowledge of the matter said.

Joshi was Tourbillon's sector head for technology, media and telecommunications investments. The people asked not to be named discussing private matters.

Tourbillon, founded by Jason Karp and which managed $3.4 billion as of earlier this year, has been losing money over the past two years.

The Tourbillon Global Master Fund lost -4.6% in November. From the start of this year through November, the fund is down -11.6%, according to an investor update seen by Business Insider. Last year, the fund dropped -9.2%.

Karp has been warning of "frothy speculation" in the markets and has been preaching patience in client letters.

Before launching Tourbillon, Karp was a portfolio manager at Steve Cohen's SAC Capital and a co-chief investment officer at Carlson Capital.