Interest Rate Risk: TLT tracks long-term Treasury bonds. When interest rates rise, bond prices typically fall, decreasing TLT's value. Conversely, falling interest rates usually increase TLT's value.

Inflation Expectations: Higher inflation expectations erode the real value of fixed-income investments like Treasury bonds, leading to lower prices and thus a lower TLT price. Lower inflation expectations tend to boost TLT.

Economic Growth: Strong economic growth often leads to higher interest rates as the Federal Reserve attempts to control inflation, negatively impacting TLT. Slowing growth can lead to lower rates and a higher TLT price.

Federal Reserve Policy: The Fed's monetary policy decisions, such as adjusting the federal funds rate or implementing quantitative easing/tightening, significantly influence interest rates and bond yields, directly affecting TLT's value.

Geopolitical Events: Major geopolitical events, especially those causing economic uncertainty, can drive investors towards safe-haven assets like Treasury bonds, increasing demand and potentially raising TLT's price.