Exchange Traded Notes - ETN
ETNs are unsecured debt securities. When held to maturity, the investor will receive a cash payment that is linked to the performance of the corresponding market index, minus fees, during the period. Holders do not receive any coupon payments during the life of the note and there is no principal protection for the investment. 
The underwriting bank promises to pay the amount reflected in the index, minus fees upon maturity. If there is any reduction of credit ratings of the bank, or if the underwriting bank goes bankrupt the value of the investment will be effected.
As debt securities, ETNs don't actually own anything they are tracking. Because the investor fee reduces the amount of return at maturity or upon redemption, if the value of the underlying decreases or does not increase significantly, the investor may receive less than the principal amount of investment at maturity or upon redemption.
c.1200 Earthen incline, edge of a river, slope, shelf, financial institution. 15c both meaning "table" (the notion is of the moneylender's exchange table), bank "bench. To put confidence in, is attested from 1884. Bank holiday is from 1871. To cry all the way to the bank was coined 1956.  bankrupt 1530s, from, a broken bench, moneylender's shop, bench broken, defeated, interrupted to break, So called from the habit of breaking the bench of bankrupts.  115c rupture the breaking (of an arm or leg), fracture, to break, to seize, rob, plunder, to tear, break.