问题如下：
An arbitrage transaction generates a net inflow of funds:
选项：
A. throughout the holding period.
B. at the end of the holding period.
C. at the start of the holding period.
解释：
C is correct.
Arbitrage is a type of transaction undertaken when two assets or portfolios produce identical results but sell for different prices. A trader buys the asset or portfolio with the lower price and sells the asset or portfolio with the higher price, generating a net inflow of funds at the start of the holding period. Because the two assets or portfolios produce identical results, a long position in one and short position in the other means that at the end of the holding period, the payoffs offset. Therefore, there is no money gained or lost at the end of the holding period, so there is no risk.
听了课之后，有一点不理解，如果两个相反的头寸最终能够offset，那这不应该是对冲吗？为什么是套利呢？越听越晕了