In mid-2017, Yahoo sold part of itself to Verizon. After the sale, they then changed their name and ticker symbol. Listed below are steps for how to make this change:
If you use Club Accounting 3, open the Yahoo security profile by clicking Securities and then Yahoo from the securities list. Change the name to Altaba and ticker symbol to AABA for that profile.

If you use myiclub.com, click the more.. link under Securities. Choose Security Settings. Click the pencil icon next to the Yahoo name. Change the name to Altaba and ticker to AABA.

Your entire Yahoo history will now appear under Altaba after the name change.