Answer:
Other customers of the firm who place buy orders, if the firm has information barriers in place.
Explanation:
FINRA has strict rules against front running, and this is the process by which interested parties place orders for shares beforehand because they have insider information on how a share is going to perform in the future.
This rule is binding on any registered representative.
However if the firm has information barriers in place, any other customers that places a buy order will be assumed not to have insider knowledge of the share's expected performance. The FINRA rule is not binding on them.