Rubicon Technology Inc (RBCN)

[Enterprising Investor]

Offer to Purchase - Amendment (8/18/22)

The Offer expired as scheduled at 12:00 Midnight (New York City time), on Friday, August 12, 2022. The Depositary has advised the Purchaser that, as of the expiration of the guaranteed delivery period associated with the Offer, a total of 2,202,283 Shares were validly tendered and not properly withdrawn pursuant to the Offer, representing approximately 90.0% of the issued and outstanding Shares as of June 30, 2022.

The final proration factor, as reported by the Depositary was 50.311427% of the tendered Shares. On August 15, 2022, Purchaser accepted for payment 1,108,000 Shares that were validly tendered and not properly withdrawn pursuant to the Offer, and payment for such Shares, based on the proration factor and any adjustments to avoid purchases of fractional Shares, will be made promptly in accordance with the terms of the Offer. All Shares tendered but not accepted for payment in the Offer will be returned to the tendering stockholders.

[Proration factor increased slightly]