The most common and most likely answer to this crossword clue is the 8 letter word HOTSHOTS
I've seen this crossword clue in The Daily Telegraph
H
O
T
S
H
O
T
S
More clues leading to the result HOTSHOTS
Buddy explains!

The straight part
We know that "smart guys" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case smart guys = hotshots.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.
What does HOTSHOTS mean?
HOTSHOTS noun- Someone with exceptional skills in a certain field.
- A type of firefighter highly skilled in wildfire firefighting without external support, using basic tools that are backpacked in and manhandled about.
- A fast freight train.
- A dose of recreational drugs deliberately laced with poison.