HARRISBURG — With a demand that PSERS top executives be fired hanging in the air, those beleaguered leaders on Thursday continued to urge Pennsylvania’s largest pension fund to double down on their controversial investment strategy — by pouring $1.2 billion more into “alternative” investments promoted by high-fee Wall Street advisers.

Six board dissidents, upset at the plan’s lackluster returns, called on Thursday morning for the 15-member board to fire its executive director, Glen Grell, and its investments chief, James H. Grossman Jr., the highest-paid employee of state government.

But Grossman came out swinging Thursday afternoon at the board meeting at the PSERS fund’s office here that began only hours after his detractors delivered to the board’s chairman their written demand for his dismissal.

Grossman told the board that one of his bets had just hit the jackpot — on paper, at least. An $85 million PSERS investment, Grossman said, in a California maker of high-fashion nurses’ uniforms was worth $329 million now that the start-up had sold its shares to the public. Grossman acknowledged that PSERS, as an insider, could not sell its shares and cash in the winnings until November, at the earliest.

Grossman also made repeated shout-outs to Grell, saying that he, too, had played a key role in picking the investment.

“A four-times improvement is the grand slam,” said board member Jason Davis, an economics teacher who did not sign the ouster letter. “Well done to you and the team.”

» READ MORE: Everything you need to know about the Pennsylvania Public School Employees’ Retirement System's meetings.

PSERS — the $64 billion Public School Employees’ Retirement System — has been under investigation by prosecutors and the FBI since at least March in a probe looking into its purchases of Harrisburg real estate and into the board’s since-retracted misstatement of an exaggerated number for its investment returns.

The fund had to clear a threshold of a 6.36% average annual return over nine years to spare teachers and school employees a larger payroll deduction — and the fund’s leadership embarrassment. That bar seemed relatively low. After all, the S&P 500 index of big U.S. stocks paid more than 10% a year during those years.

At first, the board last December endorsed a figure — 6.38% — indicating that it had narrowly cleared the bar. But during the spring, it retracted that figure as flawed and said its actual return was only 6.34%, forcing newer school employees to pay more for retirement.

At the same time, a growing number of board members have grown restive with the plan’s leadership and financial performance. They complained that PSERS, by investing heavily in exotic private ventures, had missed out on gains from a booming stock market — and that its returns over the last 10 years have been below those of other state plans.

Still, those statistics didn’t seem to shake the management’s relentless focus on betting yet more money on outside money managers..

Before the move by some board members to oust Grell and Grossman, the two men had called for the plan to put $1.2 billion more into venture capital firms, real estate ventures, and hedge funds.

This was too much for the dissidents who in their letter calling for the firing dismissed these proposed investments as “business as usual” amid a crisis.

The vote on the new investments is to occur Friday, but it may be overshadowed by the push for the firings. Such a dismissal vote is not on the agenda, but any board members can call for votes on any issue. It remained unclear whether the six critics had picked up the two votes needed to form a majority on the 15-member board and force the terminations.

On Thursday, when Grell was asked about the campaign to oust him and Grossman, Grell responded, “I don’t know what you’re talking about,” and walked away.

In their letter urging the shakeup, the dissidents reacted with irritation to the fact that the management had booked an “educational” lesson for the board Thursday to be led by a top executive from Bridgewater Associates, the world’s largest hedge fund.

The letter writers noted unhappily that PSERS has paid Bridgewater $560 million in fees over the last two decades. Like many such investments, it’s unclear how much the deals will eventually yield.

In the lesson, Bob Prince, Bridgewater’s co-investment chief, sought Thursday to justify the kind of broad, complex investment approach that PSERS has followed under Grell and Grossman.

“The only way,” he said, to produce strong returns “is a diversified portfolio that cuts across asset classes” like the one his firm had helped PSERS build “over a long time.”

Ian Toner, chief executive officer of Verus, the Seattle firm the board recently hired for $810,000 to oversee investments during the FBI investigation, sounded a different note, seeming to echo the criticism of Grossman’s foes. “Simplicity in portfolio structure is often more preferable and more effective than fashionable,” Toner said.

Among the investments up for consideration Friday, one involves a company that is Philadelphia’s largest private-equity investor. Another drew attention for its deals involving a New York skyscraper once owned by the family firm of former President Donald Trump’s son-in-law, Jared Kushner. Here is a look at those two proposed deals.

LEM Multifamily Fund VI. This is the latest fund from LEM Capital, the big Philadelphia private-equity firm that invests in aging apartment complexes. LEM says its strategy is to “add value and increase rents.” Its owners include Ira Lubert, a principal in the Rivers Casino in Pittsburgh and a former board chairman for Penn State University.

PSERS has invested $210 million in other LEM funds over the last 15 years and gotten back $232 million, as of last June, with hopes of more to come. As with other private deals, it’s hard to say how good the final returns are until the investment is complete. The fund paid the firm more $8 million in fees in fiscal 2019, the last year reported.

LEM is just a sliver of PSERS’ involvement with Lubert. Over the last 20 years, it has paid more than $200 million in fees to a variety of funds he has founded.

Brookfield Strategic Real Estate Partners IV. This is the latest fund from Brookfield Asset Management, a giant Toronto-based hedge-fund manager. PSERS has committed more than $600 million to earlier Brookfield funds since 2012, and as of June 30 gotten about $400 million of that back. Last year, PSERS paid Brookfield more than $14 million in fees.

Brookfield invests in office buildings around the world. One of Brookfield’s best-known investments, by an earlier fund that included money from PSERS, was its reported $1.3 billion payment in 2018 to a company connected to the Kushner family for control of a troubled office tower at 666 Fifth Ave. The Kushners had paid $1.8 billion for the tower back, but were having trouble keeping tenants.

PSERS put $80 million in the Brookfield fund that invested in 666 Fifth, one of many properties in that fund. PSERS estimates the value of its stake had fallen to $77 million.

To be sure, PSERS investments in earlier Brookfield funds, in 2012 and 2015, have earned double-digital profits as real estate prices went up in recent years, the pension plan says. Much of that gain is still just on paper, as Brookfield has yet to sell the those properties at their estimated new, higher prices.