Aggregating data of multiple / same vlookup references

I have been trying to simplify my monthly reporting process on a portfolio's performance...The transactions tab has hundreds of individual transactions, many times buying/selling same security. A security can be also bought once but sold in partial lots over different dates. Is there any way to use VLOOKUP to return an aggregate gain/loss by each security into a summary tab? Each security has a unique ID (Symbol) - but given multiple transactions - appears many times...If there is any way to apply a SUM or AVERAGE to get the summary data - would be awesome. Attached is a sample file.
Any help appreaciated!