There are actually long-term benefits for Wall Street stockbrokers in

Passage Analysis

There are actually long-term benefits for Wall Street stockbrokers in a rapidly falling stock market in which most investors are selling and many people are losing a great deal of money.

-The passage talks about long term benefits for stock brokers in a fast declining stock market.
-Here, most investors are selling and many people are losing a great deal of money.

After all, the volume of daily transactions rises dramatically in such a market, and the stockbrokers, who receive a commission on each sale, collect a windfall of commission income
-The number of transactions per day is steeply high in such a market.
-Therefore, stockbrokers make a fortune by collecting a commission on each sale.

Prethinking

Weakener framework

What new information will make us believe less in the conclusion that there are long-term benefits for Wall Street stockbrokers in a rapidly falling stock market,

Given that
-stockbrokers in a rapidly falling stock market in which most investors are selling and many people are losing a great deal of money
-The volume of daily transactions rises dramatically in such a market, and the stockbrokers receive a commission on each sale.

Weakener 1

In the long term, after a rapid fall, the number of transactions will be extremely low.

Answer Choice Analysis

A. Some investors whose stocks are affected in a falling market have purchased their stocks on margin—i.e., on credit—and must complete payment at the full purchase price while their stocks are actually declining in value.
Whether on credit or not, the broker gets his/her payment when the market is falling. Hence this option cannot act as a weakener.

B. Many Wall Street stockbrokers sell not only stocks, but also bonds, money-market funds, and insurance-investments that might actually improve in value during a rapidly falling stock market.
This option strengthens the conclusion by giving a reason for how the brokers benefit from the fall. Hence it cannot be the right answer.

C. Only ten percent of stock-buying and selling on Wall Street is conducted on behalf of individual investors; ninety percent is conducted on behalf of institutional investors.
This does not affect the fact that brokers make a fortune during the high number of sales happening during a steep falling market. Hence this is not the right answer.

D. After a rapidly falling market, relatively few stockbrokers give up stock-trading and leave Wall Street.
This option actually strengthens the conclusion since it implies that few if any stockbrokers stop working/lose jobs in the field due to a sudden fall. This supports the situation of the brokers. Therefore, it cannot be the correct answer.

E. After a rapidly falling market, the volume of trading in the stock market generally declines and remains at a low level for an extended period of time.
This option is in line with our prethought weakener. This is the correct answer.