This has bugged me since I saw the movie. Why was the movie called 'The Brothers Bloom'?
The brothers are Stephen and Bloom. We are never given their last names and the credits don't show a last name. I would doubt that their last name is Bloom. That would have resulted in 'The Bloom Brothers' though.
From the IMDb FAQ:
Are the Bloom brothers really brothers?
Yes. At the very beginning of the movie, a caseworker can be seen opening a file cabinet and pulling out the files on young Stephen and Bloom. The file is tagged "Bloom (2)", suggesting that there must be a "Bloom (1)".
Does Bloom have a first name?
The only reference to what Bloom's first name might be comes from a con in which Stephen calls him "Victor." Whether that's his real name or only a contrived name for the con is unknown.
So, it's entirely possible that Bloom wasn't really Brody's first name, but his last name. This would make the title accurate.
I suppose it's not uncommon for people to become known more by their last name than their first. Also, Bloom is certainly not a common first name.
(This question reminds me of the Mario bros., Mario and Luigi.)
"Bloom" is also a verb, which might mean they went for an admittedly weak pun in the title.
I assumed that with them being orphans, perhaps Bloom never had a first name (i.e. he was orphaned as an infant and was just Baby Bloom) so he always went by his last name.
Bloom seems to be the last name of the brothers, as per the IMDb FAQ via coleopeterist's answer.
While that answers the basic question it leaves open why one of the brothers is highlighted by being called by the last name where the other is called by his first name, thus basically highlighting and exposing one of the brothers and de facto naming the duo and the movie after him.
In my opinion as expressed in an answer to a related question Bloom (which from now on means just the one brother referenced by that name in the movie) is obviously the main protagonist; even more the whole con story in the movie is constructed around him by his brother. With his death at the end of the movie Stephen makes the made-up story true, he sacrifices himself for his brother's happiness and future. So Bloom is not only the movie's main protagonist, he is the main protagonist "in universe" for the story Stephen constructs and for which he gives his life. This justifies that the pair and subsequently the movie are named after him.
