Arbitrage is buying something in one place and selling it at once in another place, because the price is not the same, and keeping the difference as profit. The “something” is often money itself (currency), or shares, or raw materials. The idea is that you take almost no extra risk if you buy and sell at the same time — you are living off the gap, not guessing whether prices will rise later.

Arbitrage is buying something in one placearbitrage 是在一個地方買進東西 and selling it at once in another place然後立刻在另一個地方賣出，because the price is not the same因為兩邊的價格不一樣，and keeping the difference as profit把中間的差價當作利潤留下來。The "something" is often money itself (currency)這個「東西」通常就是貨幣本身，or shares, or raw materials或股票，或原物料。The idea is that you take almost no extra risk這個想法的核心是你幾乎不用承擔額外風險 if you buy and sell at the same time只要你同時買進賣出：you are living off the gap你靠的是那個價差，not guessing whether prices will rise later而不是在猜之後價格會不會漲。

It is a finance-and-business word, quite technical. People also stretch it: regulatory arbitrage means using a gap between two sets of rules the way a trader uses a price gap. Some people use it as a verb (to arbitrage a difference), but the noun is the form you will meet first.

It is a finance-and-business word這是個金融商業用字，quite technical相當專業。People also stretch it人們也會延伸這個用法：regulatory arbitrage means using a gap between two sets of rulesregulatory arbitrage（監管套利）意思是利用兩套規則之間的落差，the way a trader uses a price gap就像交易者利用價差一樣。Some people use it as a verb有些人會把它當動詞用（to arbitrage a differenceto arbitrage a difference，意為「套利某個差價」），but the noun is the form you will meet first但你會先遇到的是名詞形式。

In ordinary life you almost never need it unless you read the business pages.

In ordinary life在日常生活裡，you almost never need it你幾乎用不到這個字，unless you read the business pages除非你會讀財經版。