London's mid-market FTSE 250 index added to its nascent winning streak Friday with its third all time high in consecutive sessions.

The index, the most sensitive to changes in the domestic economy, broke through its previous high of 18,606 Wednesday morning, set a new record closing high on Thursday and then surged onward to 18,706 on Friday morning.

It has been boosted in recent months by a relief rally in many of the stocks that were hit in the wake of last year's vote to leave the European Union. Predictably the list of top gainers also contains a fair spread of commodity producers given the sectors overwhelming presence in the U.K capital.

Kazakhstan-based copper miner, Kaz Minerals (KZMYF) , has topped the class after chalking up a return of 49.1% over the last three months, while Ukrainian iron ore pellet producer, Ferrexpo (FEEXF) , ranks in second place after rising just more than 40%.

Both companies have been supported by solid gains for commodities, with iron-ore prices up by 50% in the months since Oct. 1 while copper prices have gained more than 20%.

Electrocomponents (EENEY) , an electrical equipment distributor, is up 36.25%. It draws around 50% of its sales from the U.K. and the U.S. and has been boosted in recent months by strong revenue and margin growth in both geographic segments.

Polypipe Group, a U.K.-centric maker of plastic pipes for construction trades, has seen its shares rise by 33.32%.

After taking a steep hit in the wake of last year's vote to leave the EU, Polypipe surprised investors in November by saying that demand from residential construction and infrastructure markets has remained strong and that is has observed no adverse impact on the business following the referendum.

But investors are still hedging their bets as the U.K heads toward the exit doors, as evidenced by the share price of B&M European Value Retail, which is up more than 28% over the last three months.

As a discount retailer of food and household goods, B&M is the kind of company that does well during hard times for consumers. It draws more than 90% of its sales from the U.K. and as a result, the nascent rally for the shares could reflect continued unease among some investors over the country's pending departure from the European Union.

In sixth place on the list is ZPG, formerly Zoopla Property Group, which operates the one of the U.K.'s largest and most successful online residential real estate portals.

The shares are up 27.6% over the last three months and have nearly doubled over the previous twelve, with the company being a continued beneficiary of a runaway market for residential real estate in the U.K.

Over a longer, six month horizon, the list of top performers for the FTSE 250 remains constant except that Zoopla, B&M and Polypipe drop out, to be replaced by Just Retirement Group and challenger banks OneSavings Bank (OSVBF) , Aldermore Group and Metro Bank (MBNKF) .

All were among the hardest hit in the days and weeks after the referendum back in June but have since rebounded strongly as fears over the immediate fate of the economy proved overblown.

Just Retirement, a savings and annuity provider, saw its shares gain more than 60% over the last six months. Likewise, with OneSavings and Aldermore, while Metro Bank has added 57%.