The TSX Composite was deep in the doldrums over the course of the last week, dropping 313 points over the last four trading sessions and slipping into negative territory for the year. The materials and energy subgroups were the main culprits, as key commodities underpinning the groups hit the skids.

Here’s a look at what’s been weighing on the TSX this week. All figures are as of the close of trading Thursday.

Overall weakness in base metals prices sent the materials subgroup to the worst showing of the bunch since last Friday’s close. Concerns of slackening demand and rising Chinese production weighed on copper, while nickel continues to trade in a challenging environment, down 58 per cent since 2014. The energy subgroup suffered through a one-two punch delivered by global markets, with the International Energy Agency forecasting non-OPEC production growth will outpace the rise in demand in 2018, and a surprise build in U.S. gasoline inventories sending WTI to lows not seen since last November. While it was the third-worst performer over the course of the week, it’s worth noting the health care index has little impact on the overall composite and comprises only six constituents.  

The worst-performer on the index is neither a member of the materials nor the energy subgroups, with loyalty-rewards provider Aimia taking the inauspicious spot in the TSX doghouse. The company suspended dividends on both its common and preferred shares this week, telling the investment community it did not believe it could clear a key legal hurdle needed to provide a payout. Shares of the company have tumbled 83 per cent since Air Canada announced it would go it alone on the loyalty rewards front in 2020. Aimia derives about 70 per cent of its gross billings from its North American division, which is dominated by Aeroplan.

Baytex Energy dropped nearly 15 per cent through Thursday amid the overall swoon in oil markets. The company, which operates in the Western Canadian Sedimentary Basin, has been struggling with negative free cash flow and high debt levels in an already challenging operating environment.

Weakness in base metals markets hit both First Quantum and Hudbay Minerals over the last week. First Quantum is heavily weighted to copper production, deriving about 80 per cent of its revenue from the metal, with the remainder of its production in gold, nickel and zinc. Hudbay is marginally less exposed to the copper markets, but has substantially larger ties to zinc.