I know that 同比 is “year over year”, while 環比 is “month over month”, but can also mean “quarter over quarter”. In reality, the latter is used to compare two different periods. Therefore, if one says 環比, one may not tell which two time blocks the author is saying. If I want to say “month over month” and “quarter over quarter”, what’s the proper way of saying each (both literal and contextual)?
For example, “stock prices jumped 5% month over month, and 3% quarter over quarter”
Don't use "环比" alone, "比" means comparison in the sentence and needs a baseline.
stock prices jumped 5% month over month and 3% quarter over quarter
股价本月环比上涨5%，本季度环比上涨3% (comparison base on the current month/quarter)
or
股价每月上涨5%，每季度上涨3% (intend to describe a long period of time)
And some alternative sentences could go like this:
(unlikely to see both "month" and "quarter" in one sentence, but need a baseline for comparison anyway):
2021年3月，股价环比上涨5%。
2021年第一季度，股价环比上涨3%。
Edited:
"同比" means the same period of time, while "环比" means the last period of time.
Not suggested to define them as "year over year / month over month" when using alone.
So usually needs a time block in the same sentence to avoid ambiguous.
