These shares just led FTSE 250 to new high

It was always going to be a tall order, and the FTSE 100 is indeed looking unlikely to make a new high Thursday. Yesterday's blast to a fresh peak at 7,586 clearly used up some buying fuel, and AIM has run out of breath tantalisingly close to 1,000 for the first time since 2008. However, mid-caps are thriving, and it is here that records are falling.

Trading at just 14,951 in the bloody aftermath of the EU referendum, the FTSE 250 is up over 100 points, or 0.5%, in early trade. At 20,057, gains in the past 11 months now total 34%.

Among the biggest winners since then are miner Ferrexpo, up almost 500%, KAZ Minerals up 309%, cyber security specialist Sophos 161% and electricals distributor Electrocomponents 138%. OneSavings Bank and Metro Bank have more than doubled, too, and all but KAZ are up again Thursday.

However, Auto Trader sped to the front of the grid after Barclays upgraded its rating on the second-hand car website ahead of full-year results on 8 June. Analysts there moved to an 'overweight' stance and increased their price target by 11% to 470p.

Increasingly popular finance deals have caused a boom in new car ownership over the past few years, but these cars are now being sold in the second-hand market, threatening a sharp drop in prices.

That's held back Auto Trader shares, but wrongly, argues Barclay's Andrew Ross. It's all about volume, and here there's a "decent outlook". He thinks a free cash flow yield of 5.1% is cheap. A recent derating is an "opportunity".

Wealth manager Brewin Dolphin remains very much in favour following last month's well-received half-year results, hitting a two-year high Thursday.

Back then, finnCap financials analyst Jeremy Grime said: "The shares are underpinned by yield and either they use the cash to acquire accretive assets or they are likely to be acquired," he wrote. "The only risk is a market risk. Looks cheap." At 331p back then, he was right.

Elsewhere, kitchen supplier and Interactive Investor favouriteHowden Joinery is doing well, joined by high street bookie Ladbrokes Coral and support services titans Hays and Capita.

There are big gains, too, for satellites company Inmarsat, which has finally clawed back losses suffered following first quarter results a month ago.

Reports Thursday have Japanese tech giant SoftBank mulling a bid for Inmarsat and, despite the lack of a regulatory news announcement to either confirm or deny, traders are taking a "no smoke without fire" approach to this one.

And Sirius Minerals closed above 30p last night for the first time since November, after being confirmed as a FTSE 250 constituent in the latest FTSE index quarterly reshuffle.

Sirius, whose share price has almost doubled since late March following solid progress at its North York Moors potash mine, will take its place among the mid-caps on Monday 19th June.

This article is for information and discussion purposes only and does not form a recommendation to invest or otherwise. The value of an investment may fall. The investments referred to in this article may not be suitable for all investors, and if in doubt, an investor should seek advice from a qualified investment adviser.