Highest volume in a single stock in one day

Highest volume in a single stock in one day
Who
Unknown
When
11 February 2000
On 11 February 2000, turnover in Vodafone shares exceeded 2.1 billion shares, the biggest daily volume in a single stock on record. On 1 January 1985 Vodafone made the first ever mobile call in the UK.
In the year 2000 Vodafone was the largest company in Europe by market capitalisation and the largest mobile telecommunications company of its kind in the world, with over 65 million customers worldwide.  Vodafone handles around 50 million calls daily, 250,000 text messages every hour, over 1000 data calls every minute, with over 12 million customers in the UK alone.