The argument: caring about ETF decay for a short term investment in a volatile market is unnecessary.
Dec 4, 2015:
SPXU: 30.06 (
http://www.proshares.com/funds/spxu.html)
SH: 20.48
S&P 500: 2091.69
Today:
SPXU: 43.17
SH: 23.18
S&P 500: 1830.30
Had someone bought $10k of SPXU (S&P 3x short) on Dec 4, today they would have $14,361, a gain of 43.6% over the principal, and a profit of $4,361.
Conversely, had someone straight up shorted $30k (three times the 10k investment) of the S&P 500, they'd have today $33,749, a profit of only $3,749. That's not even included expenses and whatever if you used an ETF to do it. If you did use the SH ETF and bought $30k, today you'd have $33,955, profit of $3,955.00. More money. Ridiculous.