Best and worst stocks on the ASX at midday

The ASX is off to a good start this week thanks to some promising company reports with the S&P/ASX 200 Index (Index: ^AXJO) (ASX: XJO) gaining 0.31% by midday.

This morning's gains follow a strong performance last week in which the S&P/ASX 200 Index added 3.7% making it the best week in more than two years. On Friday both the Dow Jones and the S&P 500 finished higher.

Here are the top five best performing stocks in the index at midday today:

• Resolute Mining Limited (ASX: RSG) has jumped 8.4% to 71 cents
• Medusa Mining Limited (ASX: MML) has rallied 6.9% to $2.245
• WHITEHAVEN COAL LIMITED  (ASX: WHC) has climbed 6.1% to $1.665
• EVOLUTION FPO (ASX: EVN) has gained 6% to 88 cents
• Silver Lake Resources Limited (ASX: SLR) is up 5.7% to 74.5 cents

These are the five worst performing stocks at midday today:

• Buru Energy Limited (ASX: BRU) has plunged 16.2% to $1.65
• UGL Limited (ASX: UGL) has sunk 5.9% to $6.66
• Ansell Limited (ASX: ANN) has lost 4.6% to $18.41
• Pacific Brands Limited (ASX: PBG) has slipped 4% to 71.5 cents
• GUD Holdings Limited (ASX: GUD) is down 2.1% to $5.83