or one percent, or even one-half of one per cent.

rise or fall was all that stood between them and ruin.
"Very sorry, sir, but you know we told you when you opened the account that you must keep your margins up," Breen had said to an old man.

The old man knew; had known it all night as he lay awake, afraid to tell his wife of the sword hanging above their heads.

Knew it, too, when without her knowledge he had taken the last dollar of the little nest-egg to make good the deficit owed Breen & Co.

over and above his margins, together with some other things "not negotiable"-- not our kind of collateral but "stuff" that could "lie in the safe until he could make some other arrangement," the cashier had said with the firm's consent.
Queer safe, that of Breen & Co., and queer things went into it.