TLT undergoing a bearish breakdow to retest the bullish breakout

What is the catalyst to drive this breakdown?

A little more about the TLT.
Interest Rate Risk. As interest rates rise, the value of the fixed-income securities or other instruments held by the Fund is likely to decrease. A measure investors commonly use to determine this price sensitivity is called duration. Fixed-income securities with longer durations tend to be more sensitive to interest rate changes, usually making their prices more volatile than those of securities with shorter durations. To the extent the Fund invests a substantial portion of its assets in fixed income securities with longer duration, rising interest rates may cause the value of the Fund’s investments to decline significantly, which would adversely affect the value of the Fund. An increase in interest rates may lead to heightened volatility in the fixed-income markets and adversely affect certain fixed-income investments, including those held by the TLT Fund.

In addition, decreases in fixed income dealer market-making capacity may lead to lower trading volume, heightened volatility, wider bid-ask spreads and less transparent pricing in certain fixed-income markets. The historically low interest rate environment was created in part by the world’s major central banks keeping their overnight policy interest rates at, near or below zero percent and implementing monetary policy facilities, such as asset purchase programs, to anchor longer-term interest rates below historical levels. During periods of very low or negative interest rates, the Fund may be unable to maintain positive returns or pay dividends to Fund shareholders. Certain countries have recently experienced negative interest rates on certain fixed-income instruments. Very low or negative interest rates may magnify interest rate risk. Changing interest rates, including rates that fall below zero, may have unpredictable effects on markets, result in heightened market volatility and detract from the Fund’s performance to the extent the Fund is exposed to such interest rates.

Additionally, under certain market conditions in which interest rates are set at low levels and the market prices of portfolio securities have increased, the Fund may have a very low, or even negative yield. A low or negative yield would cause the Fund to lose money in certain conditions and over certain time periods. Central banks may increase their short-term policy rates or begin phasing out, or “tapering,” accommodative monetary policy facilities in the future. The timing, coordination, magnitude and effect of such policy changes on various markets is uncertain, and such changes in monetary policy may adversely affect the value of the Fund’s investments.