The line of investors looking to bite into Danny Meyer’s Shake Shack IPO on Friday morning was as long as the line to get into one of his Manhattan burger joints.

The initial public offering of the 14-year-old brand, which started as a single food cart in Manhattan’s Madison Square Park in 2001, soared 150 percent soon after it opened — pushing north from its $21 pricing to $52.50 as Wall Street put its money where its mouth is.

Not that he needs the cash, but Meyer, now a very successful restaurateur and head of Union Square Hospitality — which owns the Union Square Cafe, Gramercy Tavern, Blue Smoke and a handful of other brands — saw his net worth grow by $387 million in a matter of minutes.

The 56-year-old St. Louis native is hoping to use the $90 million raised from the IPO to fund a fast-paced global roll-out of the 63-unit chain — noted in its hometown of New York City for its long lines, tasty $4.55 burgers and, of course, $5 milkshakes.

At 10:37 a.m., shares had lost little of the froth of the opening minutes and were trading at $48.00 — up 129 percent.