Stock futures fell Tuesday after President Donald Trump said he had fired Lisa Cook from her job as a Federal Reserve governor, stoking concerns about the central bank's independence under the current administration.

These stocks were poised to make moves Tuesday:

Interactive Brokers was rising 4.6% after S&P Dow Jones Indices announced the online broker would be replacing Walgreens Boots Alliance in the S&P 500 at the open of trading on Thursday. Walgreens is being acquired by the private-equity firm Sycamore Partners in a deal expected to be completed soon.

Talen Energy jumped 4.2% after the power generator was selected to replace Interactive Brokers in the S&P MidCap 400 index, also starting to trade on Thursday.

Palantir Technologies dropped 1% ahead of the opening bell. Shares of Palantir, which sells AI software to manage and analyze large amounts of data, declined 1% on Monday. CEO Alex Karp unloaded more than 400,000 shares in the data-analytics company last week, according to a filing with the Securities and Exchange Commission.

Nvidia was edging up 0.2% in premarket trading after the maker of chips for artificial-intelligence applications closed up 1% and extended its streak to two trading sessions. It was the best-performing stock in the Dow Jones Industrial Average on Monday. Coming into Tuesday, Nvidia has risen 34% this year. The chip maker is scheduled to report second-quarter earnings on Wednesday.

Serina Therapeutics soared 25% after the microcap clinical-stage drugmaker said the Food and Drug Administration supported the trial for its experimental treatment for Parkinson's disease. The company said it plans to advance its SER-252 drug under the FDA's new drug application regulatory pathway. Coming into Tuesday trading, shares are up 13% so far this year.

Heico, the maker of aerospace aftermarket parts, reported fiscal third-quarter earnings of $1.26 a share, better than analysts' estimates of $1.13. Revenue of $1.15 billion topped forecasts of $1.12 billion. The stock was down 0.5% in premarket trading.

Semiconductor company Semtech posted second-quarter adjusted earnings of 41 cents a share, beating analysts' estimates by 1 cent, as revenue of $258 million rose 20% from a year earlier and topped consensus. Semtech said it expects third-quarter adjusted earnings of 44 cents a share, plus or minus 3 cents, in line with estimates. Shares fell 0.5% in premarket trading.

Earnings reports are expected Tuesday from MongoDB, Okta, Box, nCino, and PVH.