The following tables summarize Series B convertible preferred stock and the accretion of dividend activity for the three months ended March 31, 2020 (in thousands):

	Tranche 1		Tranche 2		Total
Series B Convertible Preferred Stock
Balance as of December 31, 2019	$	13,230	$	8,645	$	21,875
Cumulative dividends on Series B convertible preferred stock		165		105		270
Balance as of March 31, 2020	$	13,395	$	8,750	$	22,145

Number of Common Shares Issuable Upon Conversion
Balance as of December 31, 2019		3,308		2,161		5,469
Cumulative dividends on Series B convertible preferred stock		41		26		67
Balance as of March 31, 2020		3,349		2,187		5,536

Based on the current conversion price, the outstanding shares, including the accretion of dividends, of Series B convertible preferred stock as of March 31, 2020 would be convertible into 5,536,344, shares of the Company’s common stock. However, the conversion rate will be subject to adjustment in the event of certain instances, such as if the Company issues shares of its common stock at a price less than $4.00 per common share, subject to a minimum conversion price of $3.27 per share. As of March 31, 2020, none of the contingent conditions to adjust the total common shares to convert the shares had been met.

Each share of Series B convertible preferred stock is entitled to a cumulative annual dividend of 5% for the first six (6) years following the issuance of such share and 3% for each year thereafter, with the Company retaining the option to settle each year’s dividend after the tenth (10^th) year in cash. The dividends accrue and are payable in kind upon such time as the shares convert into the Company’s common stock. In general, the shares are not entitled to vote except in certain limited cases, including in change of control transactions where the expected price per share distributable to the Company’s stockholders is expected to be less than $4.00 per share. The Certificate of Designation with respect to the Series B convertible preferred stock further provides that in the event of, among other things, any change of control, liquidation or dissolution of the Company, the holders of the Series B convertible preferred stock will be entitled to receive, on a pari passu basis with the holders of the common stock, the same amount and form of consideration that the holders of the Company’s common stock receive (on an as-if-converted-to-common-stock basis and without regard to the Ownership Limitation applicable to the Series B convertible preferred stock).

On February 8, 2017, the Company entered into Loan and Security Agreement with each of EWB and VLL7 and VLL8 as discussed in Note 9, Financial Liabilities. In connection with the Company’s Revolving Loan Facility, the Company issued to EWB a warrant (the "EWB Warrant") to purchase up to 40,000 shares of the Company's common stock at a per share exercise price of $3.64, and in connection with the Company’s Term Loan Facility, issued to each of VLL7 and VLL8 a warrant to purchase 290,000 shares of the Company's common stock at a per share exercise price of $2.00 (the “VLL7 Warrant” and the “VLL8 Warrant,” respectively). Each of the EWB Warrant, the VLL7 Warrant and the VLL8 Warrant was immediately exercisable for cash or by net exercise and expire on February 8, 2022. On January 30, 2020, each of VLL7 and VLL8 exercised their warrant on a cashless net exercise basis, with each receiving 193,494 shares of the Company’s common stock.

On May 5, 2020, the Company entered into the Thirteenth Amendment to its Loan and Security Agreement with EWB and Thursby, as discussed in Note 9, Financial Liabilities. In connection with the Thirteenth Amendment, the Company also amended the East West Bank Warrant reducing its exercise price from $3.64 to $3.50 per share and extending the expiration date of the East West Bank Warrant from February 8, 2022 to February 8, 2023.

Below is the summary of outstanding warrants issued by the Company as of March 31, 2020:

Warrant Type

Number of Shares

Issuable Upon

Exercise

Weighted

Average

Exercise Price

Issue Date

Expiration Date

East West Bank Warrant

40,000

3.64

February 8, 2017

February 8, 2022

Exercise of outstanding stock options, vesting of restricted stock units ("RSU"), and issuance of RSUs vested but not released			1,835,402
ESPP			293,888
Shares of common stock available for grant under the 2011 Plan			412,744
Warrants to purchase common stock			40,000
Shares of common stock issuable upon conversion of Series B convertible preferred stock			7,541,449
Total			10,123,483