UnderArmour Class A stock changes to UAA from UA.

• Under Armour Class A stock changes to UAA from UA.
• Class C shares will change to "UA" from "UA.C."   Class C shares don’t have voting rights,
• The changes will be effective Dec. 7. 

The Class A shares were by far the more active, with a full-day average of 8.03 million shares traded over the past 30 days, according to FactSet, compared with the Class C share volume of 1.58 million shares.

Through Tuesday, the average daily volume over the past 30 days was about 8.5 million shares for the Class A shares, according to FactSet, and 2.1 million shares for the Class C shares.

The Class A shares closed Friday at the lowest price since July 2014. The shares have now tumbled 24% year to date through Tuesday, while rival Nike’s stock has dropped 18% and the S&P 500 index SPX has gained 8.2%.

The company didn't give a reason for changing the ticker symbols when it was announced last week.

But the company commemorated the change in tickers, and the MLB deal, by ringing the New York Stock Exchange’s opening bell Wednesday.