A positive finish to the week on Friday led to the S&P/ASX 200 (Index: ^AXJO) (ASX: XJO) ending it with a weekly gain of 0.4% or 26 points at 5905.6 points.
Unfortunately, not all shares on the benchmark index were able to follow the market higher last week.
The following shares were the worst performers on the ASX 200 during the period:
The Challenger Ltd (ASX: CGF) share price was the worst performer on the ASX 200 last week with a decline of almost 19%. Investors were hitting the sell button in a hurry after the annuities company downgraded its full year profit guidance following a disappointing first half performance. This was caused largely by increased market volatility and declines in performance fees. Management now expects to report a full year normalised net profit before tax of $545 million to $565 million in FY 2019. This will be at worst a decline of 0.5% and at best an increase of 3.2% on last year's result, whereas previous guidance was for annual growth of between 8% and 12%.
The Northern Star Resources Ltd (ASX: NST) share price wasn't far behind with a 15% decline last week. The gold mining giant's shares came under pressure after the release of its quarterly production update. The miner held firm with its full year production guidance of between 850,000 to 900,000 ounces but warned of rising costs. Northern Star's shares are still up almost 37% over the last 12 months.
The AMP Limited (ASX: AMP) share price tumbled 12% lower last week. Investors sold off the embattled financial services company's shares after it released an update ahead of earnings season. That update revealed that AMP expects its profit to come in at $30 million in FY 2018, down a massive 96% on FY 2017's result. It also advised that its board intends to declare a final dividend of 4 cents per share, which is 72% lower than the 14.5 cents per share it paid in the prior corresponding period.
The ResMed Inc. (ASX: RMD) share price fell 11% last week. The sleep treatment-focused medical device company released its second quarter results on Friday. As you might have guessed from the share price decline, its results fell short of the market's lofty expectations. Although ResMed posted an 8% increase in revenue to US$651.1 million and GAAP diluted earnings per share of 86 U.S. cents, the market was looking for quarterly revenue of US$666.98 million and earnings per share of 93 U.S. cents. Weak sales in Europe, Asia, and other international markets were largely behind the softer than expected sales growth.