The first batch of questions were deemed too similar to another post (it wasn't) and were closed... so I've made another attempt here, hopefully better worded this time.

Some background: We have a relationship here. Securities (coins) and currencies (base coins) form a pair. A pair and a broker form an asset (I treat each broker/pair as a specific asset)

I also have a foreign exchange table that stores real-time currency exchange rates.

In my transaction history table (history_price), there is a column that contains a lot of NULL (Euro volume), and I do calculations based on the volume. What I want to do is populate it, and to do this I have to (for each NULL row):

Here's how I segment the query:

1-Find currency

SELECT `history_price`.`param_basecoin`.`Symbol` FROM `history_price`.`param_asset` INNER JOIN `param_pair` ON `history_price`.`param_asset`.`id_pair` = `history_price`.`param_pair`.`pair_id` INNER JOIN `history_price`.`param_basecoin` ON `history_price`.`param_pair`.`Coin2_id` = `history_price`.`param_basecoin`.`basecoin_id` WHERE `history_price`.`param_asset`.`Ticker` LIKE '???'

2-Find exchange rate

SELECT `Rate` FROM `history_price`.`param_forex` WHERE `Coin` LIKE '???' AND `Basecoin` LIKE 'EUR'

3-Update Euro column

UPDATE `history_price` SET `history_price`.`eur_v` = (`history_price`.`Basecoin_v` * ???) WHERE `history_price`.`eur_v` IS NULL

4- Insert 2 into 3

UPDATE `history_price` SET `history_price`.`eur_v` = (`history_price`.`Basecoin_v` * (SELECT `Rate` FROM `history_price`.`param_forex` WHERE `Coin` LIKE '???' AND `Basecoin` LIKE 'EUR')) WHERE `history_price`.`eur_v` IS NULL

5- Insert 1 into 4

UPDATE `history_price` SET `history_price`.`eur_v` = (`history_price`.`Basecoin_v` * ( SELECT `Rate` FROM `history_price`.`param_forex` WHERE `Coin` LIKE ( SELECT `history_price`.`param_basecoin`.`Symbol` FROM `history_price`.`param_asset` INNER JOIN `param_pair` ON `history_price`.`param_asset`.`id_pair` = `history_price`.`param_pair`.`pair_id` INNER JOIN `history_price`.`param_basecoin` ON `history_price`.`param_pair`.`Coin2_id` = `history_price`.`param_basecoin`.`basecoin_id` WHERE `history_price`.`param_asset`.`Ticker` LIKE `history_price`.`Ticker` ) AND `Basecoin` LIKE 'EUR' ) ) WHERE `history_price`.`eur_v` IS NULL;

It does work, but it's too slow... Is there any way to optimize it and make it faster?

UPDATE history_price AS hp JOIN param_asset AS pa ON pa.Ticker = hp.Ticker JOIN param_pair AS pp ON pp.id_pair = pa.id_pair JOIN param_basecoin AS pb ON pb.basecoin_id = pp.Coin2_id JOIN param_forex AS pf ON pf.Coin = pb.Symbol SET hp.eur_v = hp.Basecoin_v * pf.Rate WHERE pf.Basecoin = 'EUR' AND hp.eur_v IS NULL