強い経済の基礎条件ではなく、利益を逃したくないという投資家心理によって起こる、金融市場の急速で広い上昇。
"Some analysts are warning that the current stock market behavior looks less like a bull run and more like a melt up."
The question isn't whether stocks are going up — it's whether this is a genuine bull market or a dangerous melt-up.
— Common phrasing in financial commentary; widely used in publications such as Bloomberg and The Wall Street Journal during the 2017–2018 market rally