League-of-legends – Does Vladimir’s Sanguine Pool have a hidden movement speed buff

The description for Vladimir's Sanguine Pool is:

(Active): Vladimir sinks into a pool of blood becoming untargetable
for 2 seconds and slowing enemies above him by 40% for 1 second.
Additionally, he deals magic damage every half second to them and
heals himself for 12.5% of the damage done.

Nowhere in the description does it describe any sort of movement speed buff yet when I see a Vladimir use his pool it feels like he is moving faster. But because I don't own Vladimir I was never really able to test it out.

Now earlier I was looking at the last large patch update and I see this:

Vladimir – Sanguine Pool: movement speed bonus now decays over time.

So my question is: Is there a hidden movement speed buff on Vladimir's Sanguine Pool and if so, how much is the movement speed buff?