Net Income Per Share (Tables)

12 Months Ended

Dec. 31, 2020

Reconciliation of Common Shares Used for Basic and Diluted Earnings Per Share

The following table provides a reconciliation of the common shares used for basic net income per share to the diluted shares used for diluted net income per share:


Year Ended December 31,	2020	2019	2018
Basic weighted average shares outstanding	46,147,062	45,954,908	45,665,883
Effect of potential dilutive shares(1):
Warrants	—	—	441,104
Stock options	—	—	—
Restricted stock units	—	—	77,572
Performance stock units (2)	—	—	375,276
Diluted weighted average shares outstanding	46,147,062	45,954,908	46,559,835
Anti-dilutive shares excluded from the above reconciliation
Stock options	16,121	16,667	16,667
Warrants	4,877,754	4,877,783	—
Restricted stock units	302,145	249,263	—
Performance stock units (2)	1,002,501	872,258	—

(1)For the years ended December 31, 2020 and 2019 , Ambac had a net loss and accordingly excluded all potentially dilutive securities from the determination of diluted loss per share as their impact was anti-dilutive.

(2)Performance stock units are reflected based on the performance metrics through the balance sheet date. Vesting of these units is

contingent upon meeting certain performance metrics. Although a portion of these performance metrics have been achieved as of the respective period end, it is possible that awards may no longer meet the metric at the end of the performance period.