A block of shares (7)
I believe the answer is:
tranche
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">a block of shares</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for tranche that I've seen before include "Block of shares, say" , "Part or block of something" , "Portion of something, money perhaps" , "portion of shares" , "batch supplied" .)