Don't forget the management fees of these funds.
From the prospectus:
http://www.direxionfunds.com/pdfs/Investor_Class_12.29.pdf
Total Market Bull 2.5X Fund Investor Class/ Service Class
Management Fees 0.75% / 0.75%
Distribution and/or Service (12b-1) Fees 0.25% / 0.75%
Other Expenses(3) 0.56% / 0.56%
Total Annual Operating Expenses 1.56% / 2.06%
Total Market Bear 2.5X Fund
Management Fees 0.75% / 0.75%
Distribution and/or Service (12b-1) Fees 0.25% / 0.75%
Other Expenses(3) 0.68% / 0.68%
Total Annual Operating Expenses 1.68% / 2.18%
Put your commisions and trading fees on top of that.
It is an interesting concept, but I'd have to look closely to see if it was worth the fees for the risk/reward ratio's invovled.