Why The Hulk hasn't yet landed himself his own solo film has been the question amongst many Marvel movie fans for quite some time now.

Years ago Marvel was prevented to do so because the rights of the character belonged to Universal Studios, however this has been revealed to not be so anymore, and not since 2005.

The character has gained immense popularity since his debut in 'The Avengers' and despite this no Hulk solo film has yet been announced.

A recent report from Forbes claims to have the reason as to why Marvel is now holding back on the idea.

One of the big outliers listed is the money to fund the project. The last two Hulk films released did terribly at the box office and the cost for producing an effective movie now wouldn't be lucrative enough for the studio.

"The earlier film had a $137 million budget and the later production cost $150 million, so the proximity of their box office is mirrored in the closeness of their respective budgets as well. The brand didn't grow, in other words, and both films failed to break even in theatrical dollars. The Incredible Hulk did enjoy a very healthy roughly $120+ million on worldwide home entertainment, but that is offset quite a bit by marketing costs that came in at about $80+ million.

"If Marvel is going to invest $150-200 million in a superhero movie, they need to feel confident they'll see more than perhaps $40 million in eventual profit a few years down the road. They can invest that sort of money into properties they know or strongly suspect will deliver huge returns, so expecting them to invest in a franchise that's twice failed to even cover its own expenses at the box office isn't very reasonable," writes Forbes.

The other reason simply suggest that the character works better in an ensemble cast such as the Avengers. On his own the Hulk loses some of his appeal.

"The Hulk character has proven immensely popular in the Marvel Avengers team-up films, but he doesn't have to shoulder an entire film and isn't on screen for most of the running time. Which brings us to the second primary reason Marvel hasn't made a Hulk sequel film - the character seems to work better and be more popular as a value-added addition to other films. Saving the Hulk to turn him into a "special event" character whom audiences only get to see as an extra element in Marvel's biggest productions raises his profile and ensures people don't get tired of him. It also allows the movies to exploit his strengths as a character with far less concern about any potential weaknesses," writes Forbes.