select * from (Select symbol,count( distinct origin_address) as purchaser, count(tx_id) as n_purchase_txn, n_purchase_txn/purchaser as average_txn_per_purchaser FROM polygon.udm_events
WHERE to_label like 'opensea' and event_type='erc20_transfer'
group by 1 order by 2 desc)where symbol is not null --symbol='WETH' or symbol='DAI' or symbol='MATIC' or symbol='WMATIC'
limit 5