The S&P/ASX 200 Index (ASX: XJO) has started 2021 in style and stormed notably higher last week. The benchmark index rose a sizeable 2.6% to end the five days at 6,757.9 points. Unfortunately, not all shares on the index climbed higher with the market. Here’s why these ASX 200 shares were the worst performers last week: The Link share price was the worst performer on the ASX 200 last week by some distance with a 16.2% decline. Investors sold off the administration services company’s shares after its released an update on a takeover approach by SS&C Technology Holdings. Last month the NASDAQ listed global provider of investment and financial software made a conditional offer of $5.65 per share to acquire 100% of Link. While management felt the offer undervalued the company, it granted SS&C Technology due diligence. However, last week it revealed that the takeover proposal has now been withdrawn.