Why? What kinds of things might you be able to do through your wife that require all this scrutiny?
The wife may have knowledge about $bigco buying or selling $bigthing, and the husband may gain that same knowledge from her, even if she's honest and never intentionally disclosed it. (people aren't perfect and clues can slip, or he simply has access to her laptop or that scratch pad where she wrote down the essentials of a phone call etc.
At the most basic level, I worked for a company that wouldn't let you sell company stock, even as a non-executive, during a window around earnings being reported.