The most common and most likely answer to this crossword clue is the 7 letter word DOT-COM
I've seen this crossword clue in Financial Times
D
O
T
-
C
O
M
Buddy explains!

The straight part
We know that "Internet trade" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case internet trade = dot-com.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 DOT-COM mean?
DOT-COM noun- A company whose business is based around a website or primarily via the Internet.
- To convert to using or being based on e-commerce.