Interactive transaction summary

Hello Guys,

I'm making a transaction summary with numbers and I need some help. I already made a tab where i put all my transactions in. Lets say I make 2 transactions for apple stock. With sumif command I can already count the total of stocks. But now I need to import the name of the stock to the summary page without making duplicate names. So I think I need something like an =ARRAYFORMULA with an exception of duplicates.

Can somebuddy please help me?