Column: Investors surge back into oil on rising economic optimism
Portfolio investors have piled back into petroleum futures and options at the fastest rate for more than two years as concerns about a global business cycle downturn have eased.
Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction: Column: Investors surge back into oil on rising economic optimism

### Response: Portfolio investors have piled back into petroleum futures and options at the fastest rate for more than two years as concerns about a global business cycle downturn have eased.