This Is Going to Be Huge

A character sings the praises of, or announces he has invested in, something he claims is going to revolutionize society or be enormously successful; however, the show is set in the past and the audience knows he is doomed to failure. Often comes right after the character says its competition will never catch on.

This trope does not apply to Real Life because it requires an audience with hindsight; see Magnum Opus Dissonance instead. If the upcoming failure should be obvious at the time the claim is made, then that's just the person being dumb.

Contrast It Will Never Catch On, the inverse of this trope.

Film

 * At the end of Fun with Dick and Jane, the protagonists have duped the evil CEO into reimbursing all of his employees' stolen pensions, are wealthy again and are happily driving towards the sunset... until a former colleague of Dick's drives next to him and tells him he got a great job at a company called Enron...and the credits roll.
 * Near the end of Grease, the principal announces over the intercom that the graduating seniors may go on to greatness. One possible glorious future (this scene being set in the late spring of 1959) she speculates they might look forward to? Being the next Vice-President Nixon.
 * In Shanghai Knights, Roy O'Bannon wastes most of his money writing false biographies of himself under a pen name. When Chon Wang finds out, he is disgusted with Roy, but Roy claims he has invested the rest into something that will revolutionize travel - zeppelining. When Chon is still not convinced, Roy claims that it's at least more likely to happen than some crazy invention called an "automobile".

Live-Action TV

 * Done in Cold Case in a brilliant example of Fridge Logic paved with Black Humour. A '70s Disco dancer's reason to break with his conservative Jewish father is that without his strict supervision he "will live forever, like Disco". An hour later, he is dead.
 * In an episode of Teen Angel where the titular character travels back in time, we learn that shortly prior to his death, he had made a huge investment in "Planet Macarena" stock. After his future self warns him about this mistake, he then announces to "present" Steve that he will sell all his stock...and invest it in Tony Danza T-shirts.

Webcomics

 * In an Alien Loves Predator strip, we learn that while Abe and Preston were in college in 1999, the former had decided to invest all his textbook money in shares of Pets.com, the unofficial poster child of the dot-com crash.

Western Animation
"Stu: Did you know that sales of disco were up 400% in the year ending 1978? If these trends continue... ayyyyy!"
 * The Simpsons:
 * Disco Stu does this, trying to recruit for his disco record label:


 * In the episode "Homer's Barbershop Quartet", which was set in the late 80's, Homer says of Dexy's Midnight Runners, "We haven't seen the last of them!" (Well, DMR did have more success in the UK than in the US). The Italian dubbing for the episode substitutes Duran Duran to DMR, making the joke pointless since the original line-up came back together in early '00s.
 * In the episode "That '90s Show", Homer chooses records over CDs, a typewriter over a computer, and Enron stock over Microsoft stock when splitting his and Marge's possessions.
 * The Simpsons offers a slightly sneaky version of this trope in an early episode in which Bill Cosby compares Jazz to "the New Coke: It'll be around forever."