According to Bloomberg, lower fuel prices have led a resurgence in buying used Airbus and Boeing aircraft, dampening the performance of Bombardier $5.4 billion CSeries program.

Bloomberg said that there has been almost a 1,000 sales and leases of used Airbus A319s and Boeing 737-700s since the start of 2011, which is nearly four times the number of firm orders for CSeries aircraft.

Additionally, Bloomberg noted that the slump in CSeries sales, which dates to September of last year, has caused Bombardier to “bleed cash” and become “Canada’s worst-performing industrial stock of 2015.”