Manchester United's defeat at Tottenham left them four points off a top-four place

Manchester United's value has fallen by more than £400m since the start of the season.

United's share price on the New York stock exchange was $18.37 (£12.84) when they kicked off the season with a 1-0 win against Tottenham last August.

Twenty four hours after the return fixture on Sunday, a 3-0 defeat at White Hart Lane, the share price had fallen by 25 per cent to $13.83 (£9.67).

Sky Sports News HQ investigates why Manchester United has lost value on the stock exchange. Sky Sports News HQ investigates why Manchester United has lost value on the stock exchange.

United's poor performances on the pitch have been reflected by falls in the share price and the value of the club.

At the start of the season United's market capitalisation was £2bn. On Monday night it had fallen by £412m to £1.58bn.

Since Louis van Gaal started work as manager in the summer of 2014 almost a billion dollars has been wiped off the value of the club.

On 22 July 2015, United had a market capitalisation of £2.23bn. On Monday night it was down £650m to £1.58bn.

Defeat at Wolfsburg in December saw United eliminated from the Champions League

United's poor performance in this season's Champions League and problems qualifying for the next season's competition are having a significant impact on the share price.

Dropping out of the Champions League after losing to Wolfsburg in December caused the share price to fall by five per cent to $17.82 (£12.45). It has continued to fall as United have struggled to secure a top-four finish in the Premier League.

In February, the share price fell below the 2012 $14 (£9.78) flotation level for the first time. In the same month United announced a record quarterly profit of £18.6m.

Off the pitch, business is booming and United are on course to overtake Real Madrid as the world's richest club.

Louis van Gaal has one year still to run on his Old Trafford contract

Commercial revenues have been rising thanks to a record £750m Adidas kit deal and new partnerships with companies such as Gulf Oil and 20th Century Fox. More riches are on the way with a lucrative new Premier League broadcasting deal starting next season.

On the pitch, performances have fallen a long way below the standards set by Sir Alex Ferguson. United are four points away from a Champions League place with six games left to play this season. They also have an FA Cup quarter-final replay at West Ham United on Wednesday.

Missing out on the Champions League for the second time in three seasons will cost the club at least £50m and increase the speculation surrounding the future of Van Gaal. The manager's three-year contract runs out in the summer of 2017.