Is this really just about the market? I imagine it's also about a ton of body bags coming back just around the midterms. Because that will happen in a ground war.
There was never a buildup of even 1/50th of the ground forces that would have been required to occupy the major military sites, industrial sites and large cities (nevermind attempt to control the countryside). The buildup to the 2003 Iraq War started 12+ months in advance with thousands of vehicles, cargo containers, equipment and 150,000+ guys collecting in bases in Kuwait.
Iran is also considerably more mountainous than Iraq, if one looks at a topo map of Iraq and examines all the generally 'flat, somewhere generally near the Euphrates' area vs a population density map in people per square km. Yeah there's more complicated terrain in the northern part of the country, but nowhere on the size/scale of what exists in Iran.