The 1Q21 EPS season is mostly in the books, with retailers the last group to report over the next two weeks. The results were impressive -- but came against an easy comparison with last year's 1Q, when the world started to shut down to fight COVID-19. Through early May, Refinitiv reported that S&P 500 earnings rose 50.4% year over year -- the best quarter since 1Q2010. Some 87% of companies have come in ahead of expectations, up from the prior four-quarter average of 76%, according to Refinitiv. Where is the growth? Consumer Discretionary remains atop the list with a 170% earnings increase. Financials is second at 130%. Only Industrials is expected to remain negative -- with a 2% decline. Even the Energy sector, expected to have an earnings decrease at the start of the quarter, is now poised for 8% growth. Our analysts are always on the lookout for companies that raise their outlooks during earnings season. Management's ability to "raise guidance" can often be a catalyst for strong returns in the quarters ahead. Here are 20 BUY-rated companies in Argus coverage at which management has raised guidance or increased its outlook during the 1Q21 EPS reporting season.