The most common and most likely answer to this crossword clue is the 6 letter word ROYALS
I've seen this crossword clue in Financial Times
R
O
Y
A
L
S
Buddy explains!
The straight part
We know that "sovereigns" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sovereigns = royals.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 ROYALS mean?
ROYALS noun- A royal person; a member of a royal family.
- A standard size of printing paper, measuring 25 by 20 inches.
- A standard size of writing paper, measuring 24 by 19 inches.
- The Australian decimal currency intended to replace the pound in 1966; was changed to "dollar" before it was actually circulated.
- Any of various lycaenid butterflies.
- The fourth tine of an antler's beam.
- A stag with twelve points (six on each antler).
- In large sailing ships, square sail over the topgallant sail.
- An old English gold coin, the rial.
- A small mortar.
- In auction bridge, a royal spade.
- A tuft of beard on the lower lip.
- (campanology) Bell changes rung on ten bells.