How did the UK's Warren Buffett make his money?

The surprise departure of Neil Woodford has prompted some analysts to suggest that now is the time to exit Invesco Pereptual funds - led to such success by Woodford during his 25 years with Invesco.

Hargreaves Lansdown has temporarily suspended Invesco Perpetual from their Wealth 150 index and recommend that new investors wait until the new manager has taken over the fund.

It's a timely departure given the announcement of the Nobel prize for economic sciences yesterday. Our editor Allister Heath asked how, given the insights of Eugene Fama, it could be the case that some stars continue to beat markets.

Fama is the father of the Efficient Market Hypothesis (EMH), which tells us that assets traded on markets reflect all available information.

Heath says that "for ordinary investors, a variant of the efficient market hypothesis holds in practice, which is why so many people now invest in tracker funds and exchange traded funds".

That leads many people to think that those who offer market beating returns are pedalling a lie. Claims of past returns mean nothing if they can't be used to predict future moves.

So what could have made Woodford so extraordinary? The stocks he picked, or the way he picked them perhaps?

Well not if you believe that what Woodford has really been doing is choosing high risk options. Almost all economists agree that riskier activities will require higher compensation. So you can beat the market, if your risk appetite is higher - and if you luck out. Maybe Woodford has been consistently lucky. But 25 years of luck would be very surprising, and Woodford tends to pick big brands, not the smaller firms you'd associate with greater risk.

Another option is that Woodford's activism pays off for him. If you're outside the industry and have heard of Woodford before this piece - it's probably because he's incredibly vocal. He was one of the first industry people to condemn Labour leader Ed Miliband's assault on the energy firms, and he led a vocal opposition to a merger between BAE and EADS last year.

Or it's another aspect of Woodford's strategy - his long term nature when it comes to making portfolio picks. He'll sit on big name stocks for a long time, taking the bumper dividends and reinvesting them. But there's certainly no clear winning method here. When Woodford dumped Tesco 167m Tesco shares last year, the person who would snap them up was none other than investment guru Warren Buffett.

Jason Hollands, managing director of Bestinvest, notes that 2013 has seen a string of high profile exits from money management. Retirements announced so far include Jupiter's Tony Nutt and Fidelity's Antony Bolton, as well the exit of Fidelity's Sanjeev Shah from managing money.

You might begin to ask where this winning talent is going - and whether the next generation can be as stunningly successful.