NEW YORK — When David Caspe and Jordan Cahan began developing a fictional show about the Wall Street crash of 1987, the world was just emerging from the 2008 financial crisis. The pair sought to illuminate that present by shining a light on the past.

As the years wore on without a network greenlight, the project seemed less and less relevant, with the markets continuing to rise.

So much for that.

“To see the Dow drop 400 points and then drop another 400 points, and then spike and then go down again — this feels timely in a way we could not have planned,” Caspe said.

"It’s a cheesy line we like to say but it’s true: ‘Look how far we haven’t come,’ " said Cahan.

“Black Monday,” which premieres on Showtime on Jan. 20, examines what happens when an ever-steeper climb of the financial markets is followed by a resounding crash, and the colorful group of traders who choose to ride that roller coaster. To people who’ve followed the markets in recent months — after years of historic highs, the Dow had its worst week in nearly a decade this December — the show will seem like it was written about the present (minus the fashions and frequent public drug use).

That makes it both eerily relevant and perhaps even oddly prophetic.

The half-hour dramedy centers on a boutique investment firm in 1986 run by Don Cheadle’s Maurice, a brash fast-talker who really doesn’t like that his company is the “11th-biggest” on the Street. His plan for fixing it comes via Andrew Rannells' Blair, an eager recent business-school graduate with an algorithm he thinks can beat the market — although Maurice has a different use in mind for him.

Along with other misfits, including Regina Hall’s Dawn and Paul Scheer’s Keith, the firm aims to take on the dominant white-male elite firms, particularly a pair of smug-as-rain twins who run the powerhouse Lehman Brothers (okay, another period touch).

Individual machinations aside, the overall impression left is that of a banking community oblivious to the pain it will soon face.

And that could make it as fresh now as that October 1987 day it’s building up to.

“Obviously we’re not making a documentary,” Cheadle said. “But I think the reason it feels so relevant is that human greed was never excised from the process. No matter what regulations are put in place [after a crash], people find a way around it because the potential upside is just so great.”

Those regulations may not even be as strong as they were even a few years ago.

The 2008 financial crisis gave rise to a number of stronger consumer protections, most notably Dodd-Frank in 2010. But under a Republican-controlled Congress and White House, that set of regulations was substantially weakened last year. A recent Washington Post analysis found that many of the people who helped craft those safeguards now work on Wall Street.

“We’re comedy writers, not financial wizards,” Cahan said. “But it seems we never really learn these lessons.”

Caspe and Cahan researched their series by reading about Wall Street malfeasance of that era — books such as “Barbarians at the Gate” and “The Predators' Ball” — as well as by talking to Caspe’s father. A commodities trader in the 1980s, the elder Caspe in the 1980′s would travel from San Francisco to Chicago every week to trade soy futures.

The stories he came back with about the excesses he witnessed — prostitutes, drugs, general debauchery — often make it into episodes. So does something called the “O’Hare Play," in which traders would bet a lot of money on a commodity and then head to the Chicago airport. If they arrived to find the investment appreciated, they set out on a nice vacation. If it cratered, they’d buy a one-way ticket and start an entirely new life somewhere else.

"A lot of it seems crazy,” Caspe said. “But that’s what was nice about setting it in the ’80s — you could be broad and still be grounded.” (That’s also one reason it made sense to have the pilot directed by Seth Rogen and Evan Goldberg, a couple of Hollywood’s current princes of outrageous comedy.)

“It’s an intriguing combination of broad comedy, but it also gives us the space to be human,” notes Rannells, whose character may come closest to that admittedly low bar.

The show had originally been set up at the network some seven years ago. But it stalled — Caspe decided to go off and create another series, the jagged-edge ABC sitcom “Happy Endings” — as Showtime was unsure of both casting and whether a period tale of financial excess would resonate. But it arrives at seemingly just the right moment.

It also comes after Showtime has explored the finance and the corporate world with some success. “Black Monday” is a funhouse-mirror extension of sorts on the current drama “Billions,” about a financial firm under legal scrutiny, and the recent “House of Lies,” a story set in the cutthroat world of management consulting in which Cheadle also played an outsize character.

But for a pure view of the market, “Black Monday” is unique, harking back to Oliver Stone’s “Wall Street” as much as it does anything currently on television.

The show also reckons with a Wall Street resistant to those outside its privileged circle — the operating dynamic in “Black Monday” is between Maurice’s firm, populated by women and people of color, and the white-male firms they’re trying to nip at.

Those who star in the series say this isn’t as period a story line as one would hope.

“I think bias is dressed up a little better in 2018,” Hall said. “But you take a wolf and put it in better clothing and it’s still a wolf.” She would have support from recent studies like the one revealing that women and minorities are still shut out of Wall Street’s most important positions, managing barely 1 percent of the industry’s $71 trillion in assets.

The actress said she spoke to several female traders from that era who told her that they responded to discrimination with a mix of acceptance and camouflage. “Even in their disgust, they grinned and bear it. They just had to make sure they didn’t make waves,” she said. “They didn’t even complain now — they just said, ‘This is what we had to do if we wanted to succeed.’ ”

The 1980s can be felt in other ways in the series. Amid the flamboyant displays of money and adrenalized trading on suitcase-sized machines is the idea of tycoons becoming the new rock stars, as figures like Michael Milken and Leona Helmsley were briefly able to do.

And, of course, the poster child for that era: Donald Trump. He rode his master of the universe status in 1987 to become the leader of the free world 30 years later.

Scheer believes one can draw a direct line between that time and this in some other ways too. “Whether it was the greed that took root in the 1980s or the FOMO that comes from Twitter and Instagram now, you can always look at what other people have and say ‘I want more,’ ” he said. “And it’s easier to act on that greed now. Everyone can make these trades. You can make these trades from your basement.”

What effect this will have on viewers — whether they will view the story as a cautionary tale or paint distinctions between the eras — remains to be seen.

The creators, at least, hope there are red flags to infer.

“We’re comedy writers, so we’re not making prescriptions,” Caspe said. “But one thing we kept thinking is about greed, and if there’s money, someone will be there to take it, and what does that do to everyone? People will take advantage no matter what safeguards are put in.”