Thursday is a big day for hedge funds and for the stock market.

You won’t see this marked on any calendar. In fact, Wall Street would prefer that this day not exist. But it does — the day by which big investors need to let hedge funds know that they are withdrawing money.

The money won’t come out until the end of the year. But managers of the hedge funds need to know how much of their stock and bond portfolios they need to liquidate ahead of time because of redemptions.

You probably noticed that the stock market has been skittish for the past month, something that I warned you might happen as October and the elections approached. There were a lot of reasons for the market’s recent large decline — rising interest rates, the mid-term elections and the reports on political wrongdoing that are about to come out.

That nervousness accelerated the past two days and people have offered plenty of excuses for this. The fact that it’s Nov. 15 is one of the oft-forgotten reasons.

I’ll get to the other big concerns that will be ongoing in a second.

But there is a concern that’s far more obvious to those who know how Wall Street works. And that’s the fact that many big investors — stung by recent big losses that likely eroded confidence in hedge funds — will probably be asking for a lot of their money back.

Nov. 15 isn’t a hard and fast deadline. But traditionally, 45 days to the end of the year has been the time when investors have had to give hedge funds the bad news.

How much will be redeemed? I see others have quoted $100 billion as the amount that was withdrawn in each of the past few years. But since the stock market was mostly climbing during those years, the withdrawals were not noticed much.

So some of the withdrawals were being made by people who simply wanted to take their gains and go sit on a beach.

Things are different right now. Gains have been hard to come by this year, especially in the technology darlings that hedge funds like to invest in. So the money being pulled out by customers isn’t likely to be replaced by new money — unless Wall Street can persuade investors that (using that tired old cliché) the market’s recent decline is a “buying opportunity.”

Wall Street, of course, thinks everything is a buying opportunity. Think of it this way — when was the last time you stepped into a car dealership and the salesman said, “This is a lousy time to buy. You should wait”?

What’s bothering the stock market, and why is Wall Street going to have a tough time convincing people about the “opportunities?”

For one thing, inflation seems to be picking up and the Federal Reserve says it is going to continue to raise interest rates. While some asset inflation is being taken care of by the stock market’s slump, rising prices in products and services seem to be an ongoing problem that the Fed will have to address.

And since President Trump has been badgering the Fed over interest rates, central bank boss Jerome Powell will need to be even more steadfast in his rate decision. If he isn’t, the Fed will lose its credibility and seem like it is yielding to political influences.

Washington is providing a number of problems for the stock market.

As I’ve been predicting, the investigations now going on will create hurdles. Last week, for instance, stock prices fell sharply after the Democrats took control of the House and promised to investigate everything Trump ever did since he’s been in diapers.

Things will get worse in that respect because — as I’ve been saying — there are a number of investigations that are going to badly hurt the Democrats and cause them to push back even harder against the White House.

The naming of a new attorney general by Trump will ensure that punches aren’t pulled and that the probes are as damaging to each side as possible.

And, of course, there is also the never-ending investigation by Special Counsel Robert Mueller, which could actually be coming to an end.

All of this, and more, will have investors on edge. And that’s not lost on the folks who will be telling hedge funds that they want out.

I left out trade wars above because they deserve a special note.

Stocks were headed for another big down day on Tuesday, following Monday’s 600-plus Dow decline, until White House adviser Larry Kudlow said that the US and China were talking again about their trade differences.

I hope they are talking because that’s how you get disputes fixed.

Wall Street rallied on Kudlow’s statement — but still closed lower — because he bashed Trump trade negotiator Peter Navarro for taking a hard line on the China talks.

All of this must be pretty confusing to the Chinese because it certainly has Wall Street puzzled. Is Kudlow the person speaking for the administration or is he just the guy in charge of calming Wall Street, where he worked for decades?

Or is Navarro in charge? Is Navarro’s hard line — essentially saying that Trump will dictate the terms of a Chinese deal — the official word?

Will Kudlow or Navarro soon be fired by the irascible president? Will they duke it out on the White House lawn?

Until those questions are answered, Wall Street will be on edge.