|
in a mortgage deal, investors would rather have a share in a big, diversified pool of mortgages than a like amount of straight mortgages because the diversification lowers risk. in and of itself, this is straightforward an uncontroversial.
however, to create this diversified pool, the bank's traders first takes maybe three weeks to buy up small groups of mortgages from smaller originators until it's got a big enough pool. meanwhile, the bank's salespeople line up investors willing to take various portions of the final pool. if they've got enough investors lined up to do a deal, they do it and hang on to the small portion of the deal that remains.
during the build-up and for the small portion that remains on the bank's books, they hedge their mortgage position with treasuries, trying to be immune to interest rate changes (i.e., if interest rate changes, hopefully mortgages go up while treasuries go down, or vice versa, so that they neither make nor lose money). however, such hedges aren't perfect even as far as interest rates go, nevermind that there are things that influence the price of mortgages that do not influence the price of treasuries (such as changing estimates of default rates).
for the build-up time and the remaining pieces, the bank can make or lose a ton of money if the traders are good or bad, respectively. conservative banks hope that the commissions they get for doing the deal ensure a profitable outcome even when their traders lose them money, and it's a bonus when the traders make them money.
*IF* that's the sort of thing they're doing in the oil business, then i have no real problem with it. however, if they are, indeed, doing outright naked speculation, then i agree, they have no business doing it these days.
|