真的浮在水上
這是字面上的用法，也是其他意思的出發點。
adjective · C1
Able to float in water or air, or able to hold other things up so that they float.
會浮的、有浮力的
核心畫面
Picture a cork sitting on water. Something underneath keeps pushing up, so it rides on the surface, and if you press it down it comes straight back. Everything buoyant describes is doing that: staying up, refusing to sink. A cork does it in water, a mood does it after bad news, a market does it when prices could have fallen.
可以想成一顆軟木塞浮在水面上。下面有一股力一直把它往上托，所以它停在上面；你把它壓下去，它還會彈回來。buoyant…更多收起
可以想成一顆軟木塞浮在水面上。下面有一股力一直把它往上托，所以它停在上面；你把它壓下去，它還會彈回來。buoyant 的幾個意思，都可以看成同一個畫面：浮著、沉不下去。軟木塞在水裡是這樣，一個人壞消息之後的心情是這樣，價格本來會跌卻沒跌的市場也是這樣。From the word’s history
The source gives the word as buoy + -ant, that is, having the quality of a buoy. A buoy is the marker that floats on the water and does not go under, which is exactly the picture the other uses borrow.
來源資料說這個字是 buoy（浮標）加上 -ant（帶有某種性質的）。浮標就是漂在水面、怎麼都不沉的那個記號。其他兩個意思，借的就是這個畫面。
Wiktionary entry 'buoyant' (kaikki:3f6f69a190036ae4:927003013): 'From buoy + -ant.'
Two branches
沉不下去的心情與市場
把「浮在水上」搬到看不見的東西上：心情和數字也可以被托著，壓不下去。
adjective · C1
Feeling happy, lively and sure that things will go well, in a way that keeps you up even when something could pull you down.
心情輕快的