Catch up on today's top five analyst upgrades with this list compiled by The Fly: 1. Ralph Lauren (RL) upgraded to Neutral from Underweight at Piper Jaffray with analyst Erinn Murphy, who remains concerned about the sustainability of Ralph Lauren's sales group, saying earnings estimates are likely to continue to grind higher given the company's "sound" cost control and favorable margin mix shift. 2. Caterpillar (CAT) upgraded to Outperform from Neutral at Baird with analyst Mig Dobre saying he believes demand growth should continue into 2019. 3. Copart (CPRT) upgraded to Buy from Hold at Gabelli with analyst Matthew Paige saying he raised his valuation multiple to 15x EBITDA from 12x to reflect the premium he believes the stock deserves relative to KAR Auction Service (KAR) given its EBITDA margin advantage and his view that current market conditions better support the salvage auction business than wholesale. 4. Arcturus Therapeutics (ARCT) upgraded to Strong Buy from Buy at WBB Securities. 5. First BanCorp (FBP) upgraded to Buy from Neutral at BofA/Merrill. This list is just a portion of The Fly's full analyst coverage. To see The Fly's full Street Research coverage, click here.