The Fed is draining liquidity from markets for longer than expected. Here’s why it’s making Wall Street nervous.

U.S. stock futures were heading higher early Monday, building on the record highs reached last week. Dow Jones Industrial Average futures added 50 points, or 0.1%. S&P 500 futures were gaining 0.2% and Nasdaq 100 futures increased 0.

The Dow crossed 44,0000 for the first time ever as stocks were on track for their best week in a year on optimism that President-elect Donald Trump's policies will boost the economy.