Just because you can do something doesn’t mean that you should. You may be perfectly capable of cross-breeding trout with electric eels, for example, but you probably shouldn’t do it unless you’re very angry at fishermen.

http://www.usatoday.com/money/perfi/columnist/waggon/story/2012-07-12/self-directed-iras/56181024/1?csp=Dailybriefing