The most common and most likely answer to this crossword clue is the 5 plus 6 letter word BLACK FRIDAY
I've seen this crossword clue in Financial Times
B
L
A
C
K
F
R
I
D
A
Y
More clues leading to the result BLACK FRIDAY
Buddy explains!

The straight part
We know that "financial crisis" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case financial crisis = black friday.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.