1. You would use '- like "the companies' holdings." 2. Parentheses first, then brackets- such as "They stole a lot of money (the approximate total was $10 million, with most coming from big banks [Bank of America, Wells Fargo] and the rest from smaller banks). As well as those other uses mentioned above.
Actually, both are correct. There are many rules of Standard Written English that have 2 correct possibilities.
The movie DC Cab: Mr. T: Hack Inspector, you always coming here to our cab company trying to tear us down! Where's a cat like you at? Hack Inspector: If you had any education, you'd know you don't end a sentence with a preposition. Tyrone: Oh, Ok- so, where's you at, *******?
De nada. *You're welcome, sir. Dang women. " Can't live with them... pass the salt." - Mr. Darcy in Married With Children.