Billionaire hedge fund manager explains why he's all in on Trump rally: 'Animal spirits matter'

Activist hedge fund manager Dan Loeb , who's more than doubled the S&P 500's return over the last two decades, told investors he doesn't plan on missing out on the final portion of this eight-year bull market and economic expansion, which has been given new life by the euphoria surrounding President Donald Trump's election.

"While we recognize that we are in the late stages of an economic cycle, experience has taught us not to miss the end of an expansive period," the Third Point manager wrote in the letter obtained by CNBC on Thursday. "This is especially true following Trump's election. Animal spirits matter in markets and despite the obstacles that the new administration will face in passing legislation, the overall pro-business environment is in sharp contrast to the last 'you didn't build it' administration's attitude towards business, enterprise, and free markets."

The well known, swashbuckling activist said that opportunities were ripe for his style of investing, disclosing that the fund had made new investments in the financials, industrial and energy sectors last quarter.

"We expect the favorable environment for our investing style to continue for three reasons: 1) Corporate activity should pick up as President Trump's tax plans are detailed and enacted; 2) Opportunities for activist and constructivist investing are robust; and 3) Combining security selection with a reasonable interpretation of the macro continues to be critical," the letter stated.

A discussion of Honeywell in the letter garnered the most attention from the market, boosting the shares in extended trading. It was unclear from the letter if the fund's position was a friendly stake or the start of a battle with the industrial conglomerate. The latter may be inevitable unless management was already planning to spin off its aerospace division, something Loeb called for in the letter.

"Third Point believes that a separation of the Aerospace unit via a spin off transaction would result in a sustained increase in shareholder value in excess of $20 billion," the letter stated. "Spinning off Aerospace would transform Honeywell into an industrial growth company with a focus on automation and productivity.'

Third Point has substantially added to the 1.4 million-share Honeywell stake reported at the end of last year, a person familiar with the fund told CNBC. Honeywell is a top-five holding of Third Point's now, the person said.

Loeb admitted that Trump is not actually at the center of his bullishness. It's actually global economic growth that's got him excited. The manager cited a Goldman Sachs forecast for global GDP growth to top 4 percent this year, double the pace of a year ago.

Third Point reported meager returns in the letter that do not seem to match Loeb's enthusiasm. Third Point returned just 5.9 percent last quarter, slightly below the S&P 500's return.

Loeb's short-term struggles mirror that of the rest of the hedge fund industry, but his long-term record stands out. Third Point returned 15.8 percent annualized since its inception in December 1996 through the end of this year's first quarter versus a 7.8 percent annual return for the S&P 500.

The letter also discusses positions in undisclosed "frac sand miners, " German utility E.On and a rights issue of Italian bank UniCredit SpA.

--With reporting by Scott Wapner

Watch: Loeb bullish on Trump trade