Share price was up around 11 per cent from 260p to more than 290p within minutes of opening, after Lloyds valued the new bank at £1.3bn.
But what will the new TSB look like?
The result of the spilt, a requirement after Lloyds was bailed out by the taxpayer, will see a generously sized banking competitor. While it won't have as many branches as some of its competitors (631) it has a generous customer base of 4.5m customers.
According to The Times it will have the sixth largest UK bank by branch network, although a check of branch numbers put it eighth by number of branches. This, The Times says, is enough to make TSB account for six per cent of branches across the UK. TSB is expected to be just outside the top five - it will be the sixth-largest UK bank by market share.
Lloyds was a large player in terms of total assets too, and splitting TSB from its bigger brother will reduce that considerably. According to relbanks.com Lloyds was the fourth largest UK bank by total assets and may hang on to that spot - Standard Chartered is a way down in fifth.
TSB won't be breaking into the so-called big five from the off - it accounts for only 4.5 per cent of the current account market - but sees itself as a major challenger. This isn't enough for Vince Cable, who the FT quotes as being frustrated by the lack of challengers to the big five. Here at last could be one.
All eyes will now be on Friday's floatation.