请问老师program trading是用来做什么的？什么时候会用？

问题如下：

Tong adds that portfolio stocks may be used to generate incremental revenue, thereby partially offsetting administrative costs but potentially creating undesirable counterparty and collateral risks.

The method that Tong suggests to add incremental revenue is:

选项：

program trading

securities lending

attribution analysis

解释：

Securities lending is typically used to offset the costs associated with portfolio management. By lending stocks, however, the investor is exposed to the credit quality of the stocks’ borrower (counterparty or credit risk) and to risks involved with the posted collateral (market risk).

A is incorrect because program trading is a strategy of buying or selling many stocks simultaneously. It is used primarily by institutional investors, typically for large-volume trades. Orders from the trader’s computer are entered directly into the market’s computer system and executed automatically.

C is incorrect because attribution analysis is not a method of generating incremental revenue. Attribution analysis is a method that helps the manager understand the sources of return.