Here are the five worst-performing blue chips so far this year

They're trading farthest from their one-year highs.

Data from the SGX showed that Noble Group, Genting Singapore PLC, Sembcorp Marine, Golden Agri-Resources, and Olam International are the worst-performing Straits Times Index (STI) constituents so far this year.

These five stocks are trading farthest from their 12-month highs, and some of these firms are also among the counters which have experienced the largest negative price change year-to-date.

As of Friday's close, Noble Group was down 43.9% from its one-year high. The group's share price has also declined 26.5% year-to-date.

Genting Singapore PLC was down 31.3% from its 52-week-high, while its current share price has slipped 12.6% year-to-date.

Meanwhile, Sembcorp Marine was 28% off its twelve-month high, with its share price down 5.9% year-to-date.

Agribusiness players Golden Agri-Resources (GAR) and Olam International were 26.3% and 26.2% off their one-year highs, respectively. GAR has suffered a 5.4% price reduction year-to-date, while Olam's share price has declined by a milder 1.7% year-to-date.