To: All Persons or Entities who purchased CoBiz Financial Inc. (“CoBiz” or the “Company”) (NASDAQGS: COBZ) stock prior to June 18, 2018. You are hereby notified that Levi & Korsinsky, LLP has commenced an investigation into the fairness of the CoBiz merger. CoBiz will be sold to BOK Financial Corporation (NASDAQGS: BOKF). Under the terms of the transaction, CoBiz shareholders will receive 0.17 shares of BOK stock and $5.70 in cash for each share of CoBiz stock they own. Based on the closing price of BOK Financial Corporation on June 15, 2018, this represents a value of approximately $23.02 per share. To learn more about the COBZ merger investigation and your rights, go to: http://www.zlk.com/mna/cobiz-financial-inc or contact Joseph E. Levi, Esq. either via email at jlevi@levikorsinsky.com or by telephone at (212) 363-7500, toll-free: (877) 363-5972. There is no cost or obligation to you.

The investigation concerns whether the Board of CoBiz breached their fiduciary duties to stockholders by failing to adequately shop the Company before agreeing to enter into this transaction, and whether BOK Financial is underpaying for CoBiz shares, thus unlawfully harming CoBiz shareholders.

Levi & Korsinsky is a national firm with offices in New York, Connecticut, California, and Washington D.C. The firm’s attorneys have extensive expertise in prosecuting securities litigation involving financial fraud, representing investors throughout the nation in securities lawsuits and have recovered hundreds of millions of dollars for aggrieved shareholders. For more information, please feel free to contact any of the attorneys listed below. Attorney advertising. Prior results do not guarantee similar outcomes.