Catch up on today's top five analyst upgrades with this list compiled by The Fly: 1. Twitter (TWTR) upgraded to Hold from Sell at Loop Capital with analyst Blake Harper saying downside is limited, even if the Q3 results disappoint, as there is "essentially a floor on the value of shares given the M&A speculation." 2. Costco (COST) upgraded to Buy from Neutral at Northcoast with analyst Chuck Cerankosky saying he expects a stronger earnings improvement in 2018 and believes the performance will reflect a $5 membership increase in the US and Canada. 3. Yum! Brands (YUM) upgraded to Outperform from Neutral at Credit Suisse with analyst Jason West citing a bullish outlook for the "New Yum" non-China, which will begin to trade on a standalone basis on November 1. 4. America's Car-Mart (CRMT) upgraded to Buy from Underperform at BofA/Merrill with analyst Elizabeth Suzuki saying she believes competition in the subprime auto market is beginning to ease and said she is seeing signs of credit tightening at other subprime lenders which should benefit Car-Mart. 5. Alon USA Partners (ALDW) and Western Refining (WNR) upgraded to Buy from Neutral at Citi. This list is just a portion of The Fly's full analyst coverage. To see The Fly's full Street Research coverage, click here.