The Inflation Reduction Act [IRA] is the largest climate legislation in US history. It includes billions of dollars in subsidies and incentives geared towards accelerating the energy transition in the United States and increasing domestic manufacturing of clean technology. This thesis conducts studies to gauge the impact of this monumental policy on US renewable energy investment markets, especially in the short-term time window designed around the dates when the IRA passed in US Congress. The results show that there are abnormally positive renewable energy stock returns and a significantly large proportion of clean energy M&A deals in the United States during the proposed time frames. These outcomes mean to show the impact of large-scale government subsidy policies on the financial markets of the industry it targets, as well as on the corporate decision-making that the legislation incentivizes. The thesis concludes that policies should heavily consider financial markets in order to achieve longer-lasting impact.