The benchmark FTSE 100 index was testing levels not seen since 2008, and the FTSE 250 index was also powering forward on Wednesday.
The large-cap FTSE 100 index moved up by 21 points, or 0.3%, to close the day at 6,359. The FTSE 250 index rallied by 127 points, or 0.9%, to close at 13,603.
The main large-cap stock that was rallying ahead was Tullow Oil (TLW). Shares in the energy exploration group were up by nearly 7% after it reported full-year results that were in line with market expectations.
Tullow's CEO, Aidan Heavey, was upbeat about the company's results in a statement issued to investors: "[Our] focus on exploration-led growth, together with active portfolio management and Tullow's strong balance sheet, provides an excellent platform for growth in 2013 and beyond.”
On the economic front, the governor of the Bank of England (BoE), Sir Mervyn King, admitted at a press conference that inflation will continue to remain above the 2% target for some time to come.
"The Monetary Policy Committee now believes that the CPI measure will remain above 2% for the next two years - [it seems] the central estimate for Q1 2015 is 2.3% - before falling back to target towards the end of 2015. This is a step up of 0.5% from November’s projection," said Investec economist, Philip Shaw.
To see the top winners and losers on the FTSE 100 each day, check out Morningstar's Heat Map.