Dow tumbles another 500 points at open, then seesaws

It’s going to be another bumpy ride.

After opening down 540 points on Tuesday morning, the Dow Jones industrial average shortly recovered, seesawing into positive territory less than 15 minutes after the open.

“This is a good sign,” Peter Cardillo, chief market economist at First Standard Financial, told The Post.

“We’re not seeing a one-way decline and we’re not rushing to a top. We’re building a base,” Cardillo siad.

The blue-chip index was off 2.3 percent at the open, to 23,810 — going deep into the red for the third straight day after stock indexes around the world had gone into the red following Monday’s US selloff..

Investors had been bracing for a rough opening, since futures trading implied a drop of about 540 points at the opening.

The VIX — known as the “fear gauge” — had also jumped above 50 for the first time since August 2015

The selloff has been due to no single factor.

An improving economy, the extra cash from the Trump tax cuts, and rising inflation are all pushing investors to unwind trades that were projected to do well under slower growth and lower inflation.

The Dow had its largest-ever point drop on Monday, collapsing 1,175 points to 24,345 — erasing all of the gains for the year. That followed a 666 point drop on Friday.

The selloff “was long overdue and when it did happen, it was pretty hefty,” Cardillo said, pointing to 15 months of uninterrupted gains.

While the drop was major in terms of points, the market fell 4.6 percent, which isn’t among the 20 biggest market drops.