It is not often one hears of a star fund manager making an abject apology to clients for poor performance.

However, this is what Neil Woodford, formerly of Invesco and now of Woodford Investment Management (after setting up his own firm three years ago), was forced to do last month.

Woodford’s main fund is the Woodford Equity Income fund, a £9.25bn giant, and one of the biggest individual equity funds in existence.

The fund suffered a dire August, with four of its largest holdings suffering precipitous large share price falls.

These included Astrazeneca (drug trial failure), Allied Minds (write down of investments and larger than expected operating losses), AA plc (profit warning and loss of CEO), and Provident Financial (profit warning, loss of CEO and FCA investigation).

Provident Financial was particularly damaging, with the share price falling by two thirds in one day, one of the biggest FTSE100 share price drops ever. According to reports, Woodford lost £326m in the stock in one day, with total losses of £560m against book cost.

Provident plunged after changes made to the way it manages its door-to-door lending, with a switch from commissioned to salaried staff following pressure from regulators.

This has affected its ability to make collections from clients.

The Home Credit division has gone from £100m expected profits to £100m expected losses in the space of a few months.

Woodford is known for taking concentrated positions in high conviction stocks.

He has been one of the biggest investors in Astrazeneca for some time, has 11% in AA and currently holds 19% of Provident Financial, or nearly a fifth of the shares.

Over the year to August, the CF Woodford Equity Income fund fell 0.3%.

In absolute terms, not a disaster, but this has to be set against a 10.5% return for the equity income sector, so it has underperformed by 10.8%.

This comes after a poor 2016, when Woodford missed out on the post-Brexit bounce in stocks, with low holdings of the large, internationally diversified US Dollar earners. He has for some time held negative views about mining stocks (and indeed anything China related), and as a result missed out on the commodity rebound of the past 18 months.

Woodford Patient Capital Trust, a closed end investment trust that has concentrated holdings in a number of early state companies, some of them unquoted, also suffered a poor 2016, dropping 10%, with the shares still below their launch price two years ago.

Prior to this, Neil Woodford had an excellent investment track record, with several well-timed tactical shifts over the years.

Thus, in the late 1990s he avoided the tech sector; in the mid-noughties he avoided the oil majors when BP and Shell went through difficult times; and before the crisis, he avoided financials. He got out of Tesco in 2012 before problems emerged there.

Since the crisis, his signature theme has been big positions in tobacco and pharmaceutical companies, alongside concerns about the strength of economic recovery, often sticking with the same companies and making little change to the portfolio.

Every investor goes through difficult patches, and other eminent fund managers like Warren Buffet and Anthony Bolton had periods of underperformance.

Where things go from here is difficult to say. Woodford is 57, so still young enough to get things back on track, though there will inevitably be an element of stock specific risk to any recovery in the funds he manages.

Astrazeneca shares have recovered. While there has been a bounce off the lows for Provident, it remains way off its highs. If Woodford changes his mind on the stock it will be extremely difficult to reduce his position, given the negative signalling this would send to the market.

Perhaps it illustrates the difficulties of being an investment manager while trying to run one’s own fund at the same time. At a bigger organisation like Invesco, there are more experienced investors around who can challenge one’s own position. There are also plenty of people to tap for specialist sector knowledge.

At the new firm there are less resources, as one would expect in a smaller organisation.

Also, it could be argued that Mr Woodford is a dominant figure, and that junior analysts may be reluctant to challenge him or perhaps lack the wider experience to do so.

For the UK’s pre-eminent fund manager, it has been a humbling two months. But no-one ever said it was going to be easy, as Neil Woodford himself would be the first to acknowledge.

The opinions stated are those of the author and should not be taken as investment advice. Any recommendations may not be suitable for all, so please contact your financial adviser for further guidance. The value of investments can go down as well as up.