美国长期国债 (Barclays U.S. 20+ Year Treasury Bond Index / NYSE 20 Year Plus Treasury Bond Index) 做多 iShares 20+ Year Treasury Bond ETF (TLT) 做空 ProShares Short 20+ Year Treasury (TBF) 两倍做多 ProShares Ultra 20+ Year Treasury(UBT) 两倍做空 债券20+美国债指数ETF-ProShares两倍做空(TBT) 三倍做多 Direxion Daily 20+ Yr Trsy Bull 3X ETF(TMF) 三倍做空 债券20+国债指数ETF-Direxion三倍做空(TMV)