As dismal employment data threw the U.S. stock market for a loop on Friday, Europe worried about rising inflation and slow economic growth.

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However, Arca wouldn't be able to trade NYSE-listed securities, taking one of the 13 U.S. stock exchanges out of the loop for brokers, according to persons familiar with the plan's working.

WSJ: U.S. Stock, Bond Markets to Close Tuesday

Authorities in the Command "Loop": As noted above, the U.N.

CENTERFORSECURITYPOLICY: Center For Security Policy

Outside the U.S., Amex has taken a step away from its closed loop model where it issues its own credit cards and also acts as the acquirer for merchants accepting the card.

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