Disclaimer: this article is purely based on speculation and numbers carried together out of interviews and news bits. Since barely any numbers have been made official a few of the numbers have to be estimated so the result won't be 100% accurate. However I tried to the best of my ability to carry together the correct data to make this article as on-point as possible
FOX is very coy on talking about the budget 2015s "Fantastic Four" recieved but given the fact that it's a pretty big title we can assume that the film cost at least $150mil to make (about $50mil more than the 2005 version as films films only get more expensive by decade, not cheaper)
The movie is currently sitting at a $160 mil. box office internationally. This includes china, one of the most significant growing markets given the fact that "Terminator: Genisys" was sitting at a dissapointingly low ammount until the china release catapulted it up to its current (09.16.15) $440 mil. international gross.
So, we might be capable of saying that it might have made back its budget. But that's the issue: a movie needs to make profit, what investors currently have is a movie that made them nothing but the money they spent to even make it. Nothing additionally, wich is the point of investing in a movie.
So we can assume that no one lost any money, right? Well that would only apply if we're going by general budget law. A movie gets funded, made, promoted, released -> that's the usual proccess.
This movie however did have a fairly unorthodox production proccess: massive reshoots and other creative leads brought in. So that estimated $150mil could EASILY be somewhere close to $200mil. Reshoots are not only tricky but also expensive: you need to recreate the vision to have the reshot material allign with the already produced material (that proccess arguably didn't work, nevertheless it certainly cost some money). Since we're being generous this movie might have had the additional cost of $30-$40 mil-.
Best Case Scenario for FOX: the movie cost $100 mil. to make and only had marginal reshoots at the low cost of $10 mil. and with home video sales this movie might make it to $200 mil. turning it into a moderate success
Worst Case Scenario for FOX: this movie stands at an original budget of $180mil ($20mil less than "X-Men: Days of Future Past", FOX' last superhero film), had almost 40% reshot that cost about the half of the original budget, so $90 mil. And is sitting at a total $270 mil. budget MINUS PR costs.
But as usual the truth is somewhere in the middle so here's my personal suspicion of where "Fantastic Four" MIGHT be at the moment:
"Fantastic Four" originally might have cost around $160 million, a budget lower than their previous hit "X-Men: Days of Future Past" and fittingly $30 million more than "Rise of the Silver Surfer" (the franchises last installment) originally cost. Keep in mind: a movies production budget 10 years ago will always be lower than current day budgets (for example: the original "Spider-Man" movie from director Sam Raimi cost $130 mil. to make while the reboot 10 years later stood at a proud $230 mil.).
As someone that followed the proccess and read most articles it's safe to say that the movie had roughly 30%-40% reshot and given the sudden plot change mid movie that makes some sense to me. And as I said: reshoots aren't cheap and are only done in case the studio has faith in a movie quality wise succeeding OR is afraid that the current quality is emberassingly low. In this case FOX probably spent quite a sum to "fix" the flick so I'm going with a $30 million budget for the reshoots (I'm being generous here, seeing how half the movie feels like a completely new movie I'm actually inclined to say that they spent an entire movie budget on the reshoots alone but that would be insane).
This would elevate the movie to a $190million budget (still less than "Days of Future Past" and "The Amazing Spider-Man").
And now we have to figure in the PR budget. Usually a studio invests about $50 million in marketing for non-blockbusters (romantic movies like Nicolas Sparks adaptions) and $80mil for big time blockbusters. F4s campaign however felt heavier than the campaigns for big budget movies like "Hunger Games: Mockingjay Part 1" and even the latest X-Men installment "Days of Future Past". The PR campaign felt as heavy as Disney's "Ant-Man", keep in mind that Disney is a studio that HEAVILY invests in it's releases and leaves almost no room for failure after the failure they suffered with "John Carter" in 2011.
If we are being hopefull "Fantastic Four" stands at the average $75 million for promotion and a total of potentially $265 million. Something that the movie is far from having crossed
Now the future of the superhero franchise might be fully in the hands of the home video release.
And again: this article is based purely on speculation, experience and the few numbers one can work with. I'm not claiming this as fact, just a potential outcome based on generalized numbers. Clearly this article won't hit the 100% accuracy level, however: this was to the best of my ability to give fans a little insight in the inner workings of the movie industry's biggest aspect, the box office