Citigroup's analyst's decision to reinstate a Buy rating on Cemex could reflect positively on Citigroup's analytical capabilities and influence in the market. This could potentially have a positive impact on Citigroup's reputation and stock price.

Analyst ratings and price targets can significantly influence a company's stock price. In this case, Citigroup's reinstatement of a Buy rating and a price target of $8.2 for Cemex indicates a positive outlook for the company, which could lead to an increase in its stock price in the short term.