Where did the idea that they are diluting the stock come from? That makes no sense. If they are retiring shares that is by definition the exact opposite.
"A reduction in the ownership percentage of a share of stock caused by the issuance of new stock. Dilution can also occur when holders of stock options (such as company employees) or holders of other optionable securities exercise their options. When the number of shares outstanding increases, each existing stockholder will own a smaller, or diluted, percentage of the company, making each share less valuable. Dilution also reduces the value of existing shares by reducing the stock's earnings per share".
Plus if the ownership was exercising their stock options, That required a report to FIRNA and the SEC.
The rise and fall is systematic of pennies.
Windfall Magic
