Image source: Getty Images. Stock markets are resilient by nature, although vulnerable to significant declines. Also, investors’ risk appetites fade when market volatility is exceptionally high. Most global stock exchanges, including the S&P/TSX Composite Index, have gone through severe corrections, yet recover every time. In 2021, the TSX’s resiliency is evident amid the raging COVID-19 pandemic. The index hasn’t succumbed to the pressure thus far and remains in positive territory with its 9.77% gain. As of May 13, 2021, the energy (+35.41%) and financial (+17.18%) sectors outperform the broader market. The rally appears unstoppable, despite the bubble warnings. I see three reasons why TSX stocks can march on and sustain their upward momentum. The index could even end the year at a record high.