My spouse wasted a lot of money on a business venture; it never was successful. Is this considered waste and dissipation?

Some states and some courts consider business losses as waste and dissipation, while others think of them as ordinary risks, for which neither party should be penalized or benefited. The court will examine the facts of the business losses, in order to make this determination. If the business losses were part of a deal that would have benefited both you and your spouse, should it succeed, and it had a reasonable chance of success, the court is more likely to consider this loss an ordinary risk.

If you were not aware of the business venture and your spouse made no attempts to make you aware of the business venture, than it would probably be considered waste or dissipation, so long as you were typically informed of such business ventures in the past.