Question

to his credit, he retained, at the time, the shares that resulted from this substantial exercise.
in the sentence above, retained has the same or almost the same meaning as:
spread out
dealt with
held back
used up

Explanation:

"Retained" means to keep or hold onto something. "Held back" also implies keeping something in one's possession or not letting it go, which is the closest in meaning. "Spread out" means to distribute over an area. "Dealt with" means to handle or take action regarding something. "Used up" means to consume or exhaust something.

Answer:

held back