But even exit screening, he says, is unlikely to have much effect because of the virus' long incubation period.

CNN: Up to three Ebola-infected travelers might fly each month

Staffing reductions are going into effect all over airports, from security-screening officials to customs officers to air-traffic controllers.

WSJ: Plan for Bigger Travel Delays

Research has also shown that screening for small-caps down significantly from their highs in mid-December respond the best to the January Effect.

FORBES: Get Ready For A Turbo Charged January Effect