There was a phrase, “surprise on the upside” with specific quotation marks in the Washington Post (June 9) article with a headline, “Trump says he’ll size up Kim Jong Un within the first minutes of summit," followed by the clause:
“Voicing optimism ahead of the summit, the president suggested the North Korean dictator will “surprise on the upside.”
I checked the meaning of “surprise on the upside” on both Oxford and Cambridge online dictionaries, neither of which doesn’t carry definitions of this phrase.
An answer in WordReference to the question on this phrase states:
“surprise on the upside” is a financial jargon and used to indicate a surprise (an unexpected result) which is positive rather than negative.”
GoogleN gram shows that the phrase started to be in use in /around 1980. The usage went up to 0.00000004% level in 1990, and plummeted to 0.000000015% level, which seems to be almost a negligible currency to me.
Does “surprise on the upside” mean unexpectedly positive outcome? Is it really a technical (financial) jargon? Can I use it in daily conversation simply for 'very good news' ?