trading halts 一般是由谁设置？

问题如下：

Since electronic trading has added systemic risk to the market, Johnson asks Martin to suggest ways to minimize the systemic risk introduced by his algorithm. Martin offers two suggestions:

• Suggestion 1 Perform extensive testing of the algorithm before its launch.

• Suggestion 2 Impose mandatory trading halts if prices change outside a threshold range.

Which of Martin’s suggestions will most likely be effective in limiting the systemic risk introduced by his algorithm?

选项：

Only Suggestion 1

Only Suggestion 2

Both Suggestion 1 and Suggestion 2

解释：

C is correct. Both suggestions will likely be effective in minimizing the systemic risk introduced by electronic trading. First, exhaustive testing of the algorithm prior to its launch can minimize risk relating to programming errors, which could result in an extreme market reaction that could trigger an even more extreme market reaction. Second, imposing mandatory trade halts in case of large price changes (outside a given threshold) would limit potential undesired results and help minimize systemic risk.