The most common and most likely answer to this crossword clue is the 8 plus 4 letter word EXCHANGE RATE
I've seen this crossword clue in The Daily Telegraph
E
X
C
H
A
N
G
E
R
A
T
E
More clues leading to the result EXCHANGE RATE
Buddy explains!
The straight part
We know that "Speed at which one can give and receive money" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case speed at which one can give and receive money = exchange rate.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.