The iPath Short Extended Russell 2000 TR Index ETN (NYSEArca: RTSA) will be history on Sept. 20, as the security plunged below its automatic redemption price of $15 a share today, making it the third iPath inverse ETN in a week to succumb to this year’s stock market rally.

RTSA fell below $15 at 1:26 p.m. Eastern time, the ETN’s sponsor Barclays Plc said today in a press release. It closed 17 percent lower today, at $15.03 a share, in part the result of the stock market’s latest leg up following the Federal Reserve’s announcement that it was launching QE3. The bond-buying program is aimed at keeping borrowing rates low and lifting asset prices, including stocks.

“Thank you, Mr. Fed,” said one industry source, who spoke to IndexUniverse on condition of anonymity, referring to how rising stock prices doomed RTSA and the two other inverse iPath ETNs that also hit their automatic redemption levels as their values crumbled in the face of rising equity prices. The S&P 500 is up almost 17 percent in 2012.

The Dow Jones industrial average rose today by 206.51 points, or 1.55 percent, to 13,539.86 in the wake of the Fed’s decision, and precious metals shot up too. The SPDR Gold Shares (NYSEArca: GLD), the world’s largest physical gold ETF, climbed more than 2 percent to $171.33, and the iShares Silver Trust (NYSEArca: SLV) added 4.35 percent to end the session at $33.61 a share.

Mechanics Of Redemptions

Holders of RTSA will receive cash payouts of $14.8054 a share on Sept. 20, the fifth day after the automatic termination date, which was today, Sept. 13, 2012.

The two other notes that are history—the iPath Short Extended S&P 500 TR Index ETN (NYSEArca: SFSA) and the iPath Short Extended Russell 1000 TR Index ETN (NYSEArca: ROSA)—both fell under their critical “automatic redemption” thresholds on Friday, Sept. 7, the bank said in two separate press releases.

The ETNs’ two prospectuses call for automatic redemptions when the intraday indicative values of the notes fall below $10 a share. The termination event occurred on Friday, Sept. 7, and the redemptions will occur on Sept. 14, Barclays said.

RTSA had $4.15 million in assets as of Sept. 11, while SFSA had $7.84 million and ROSA had $1.41 million, according to data compiled by IndexUniverse.

Barclays said in the respective press releases that further information on the redemptions is available on its product website at www.iPathETN.com, and it directed readers to sections that appear under the heading “Specific Terms of the ETNs—Automatic Termination Event.”