NEW YORK (TheStreet) -- American Express (AXP) - Get Report management has some explaining to do at its next investor day, TheStreet's Jim Cramer, co-manager of the Action Alerts PLUS portfolio, said Wednesday on CNBC's "Mad Dash" segment. 

Not only are shares down 13% for the year to date, but in the last month the company lost an antitrust lawsuit and failed to renew its exclusive contract with Costco Wholesale (COST) - Get Report. Cramer said many investors don't realize how important the contract with Costco was -- it boosted the use of the American Express card overseas. 

American Express "may not be up to the challenge" of taking on Visa (V) - Get Report and MasterCard (MA) - Get Report, which are "brilliant" companies, he added. MasterCard is an AAP holding. American Express was once an AAP holding until the charitable trust sold out its position earlier this month.

Merck & Co. MRK and American Express AXP data by YCharts

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As for Merck  (MRK) - Get Report, Cramer thinks it "could be making a comeback." Shares are up over 4% for the year to date and are up about 1% Wednesday. The company announced it will add an additional $10 billion to its stock buyback program. If the stock price remains the same, the buyback would retire roughly 7% of outstanding shares. 

Cramer also noted that the Phase III trial of Merck's melanoma treatment was stopped early after successful results were found by an independent party. 

Cramer said the stock has badly underperformed many of its peers, with shares climbing only 7.4% in the past 12 months. The company needs to continue developing new drug treatments to get the stock moving higher again, he concluded.

At the time of publication, Cramer's Action Alerts PLUS had a position in MA.