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For example, in 2011, Citigroup (C) conducted a 10:1 reverse split, each stockholder had a reduction in the number of issued shares by a ratio of 10:1
Updating Positions Effected by a Stock Split
Step 1: Navigate to the Audit / Corporate Actions page.
Step 2: Enter in the correct information paying careful attention.the Symbol, Ratio, Action Date, and New Symbol (if necessary).
Step 3: Preview the results to view all open positions on the action date and click save.