A ardvark Trading LLC will pay a $205,000 fine after CME Group Inc. said the firm’s automated trading system caused price and volume aberrations in Eurodollar futures two years ago. The exchange operator cited the ‘‘improper configuration and modification’’ of Aardvark’s automated trading system and the failure of the firm to appropriately test the code before deploying it. The enforcement action comes as the Commodity Futures Trading Commission is considering a rule that would give it easier access to automated trading firms’ source codes. The commission last year proposed that firms store their codes in a repository, to be available to the CFTC at any time (47 SRLR 2310, 12/7/15). Firms have pushed back, saying the proprietary codes are too valuable to store with third parties and turn over without a subpoena.