Fizz Runes explained
There's one set of runes for Fizz on patch 15.14 that is the clear favorite for LoL players and pros alike. The best Fizz rune paths on the position 
Mid are 
Domination as the primary path and 
Sorcery as the secondary path with a pick rate of 78%. Besides picking runes on Fizz you should learn how to play Fizz and if you are interested in pro matches take a look on how a pro builds Fizz. If you want to discuss 
Fizz then you should visit the champion subreddit.
Fizz runes from primary path
Domination improves burst damage and assassination tools on Fizz. Most of high elo players – and our LoL pros in the the major regions – have agreed that Electrocute is the best keystone rune to run on Fizz. This keystone rune provides burst damage, aiding them in nuking down the enemy carries. Other primary runes on Fizz are Sudden Impact, Grisly Mementos and Treasure Hunter.
Sudden Impact increases your damage after dashing or being invisible. This is due to how easy it is to activate on Fizz with the amount of ways he has to dash, jump or going invisible. The additional lethality helps to take down the priority targets that much easier. Treasure Hunter is the final rune of the Domination path. This rune gives Fizz additional gold for takedowns. The additional gold is nothing to scoff at and can mean the difference between winning or losing a battle. Fizz will gain an additional 70 gold for the first takedown. Fizz acquires Bounty Hunter Stacks, which Fizz may use to get more takedowns. This rune's power will grow tremendously, and Fizz will become wealthy like never been before. Each time a fresh stack of Bounty Hunter Stacks is consumed, Fizz will get an additional twenty gold.
Fizz runes from secondary path
When it comes to your secondary path, most Fizz players prefer to go with Sorcery. Sorcery empoweres abilities of Fizz and increases the available champion resources. On the Sorcery path, the best runes for Fizz are 
Transcendence and 
Scorch.
Transcendence for some more Ability Haste. Scorch increases your control in the early game.
FAQ for Fizz Runes
Which is the best keystone rune on Fizz?
The best keystone rune on Fizz is Electrocute. This Fizz runes setup is then referred as Fizz Electrocute.
What runes does Fizz use?
Runes from the paths Domination and Sorcery are the most used runes on Fizz. For the exact pick rates of Fizz runes used, you have to study the rune distribution presented.