RE:Buffett also supports share buybacks/cancelationBuybacks can be postive or negative. They can be positive when the underlying business is growing, but underpriced. They can be neutral or negative when the company is stagnant or declining and valuation is fair or overpriced.
Positive examples are autozone and teledyne. Negative examples are IBM and Sears.
Knight has been increasing sales and cash flow, and the stock is arguably very cheap. My opinion is this will lead to a positive outcome over time.