Forget about Apple or Twitter. There's a rolling bear market in transport stocks, says Cramer.
Analysts say Knight and other active acquirers will be buying during the coming trucking sector weakness.
The Deal's Lou Whiteman reports that truckers are sounding a word of caution about future growth, casting doubt on the strength of the overall economy.
American Airlines (AAL) could rally back into overhead resistance in the $50 to $55 area.
Cramer says these five groups must be approached with caution.