Condensed Balance Sheets (Parenthetical) (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Related party accrual	$ 134	$ 15
Redeemable convertible preferred stock, shares authorized		35,962,362
Redeemable convertible preferred stock, shares issued		20,390,095
Redeemable convertible preferred stock, shares outstanding		20,390,095
Redeemable convertible preferred stock, liquidation value		$ 172,037
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	0
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	500,000,000	52,000,000
Common stock, shares issued	50,949,490	4,059,909
Common stock, shares outstanding	50,949,490	4,059,909
Series A Redeemable Convertible Preferred Stock
Redeemable convertible preferred stock, par value	$ 0.001	$ 0.001
Redeemable convertible preferred stock, shares authorized	10,502,804	10,502,804
Redeemable convertible preferred stock, shares issued	0	6,225,719
Redeemable convertible preferred stock, shares outstanding	0	6,225,719
Redeemable convertible preferred stock, liquidation value	$ 0	$ 26,887
Series B Redeemable Convertible Preferred Stock
Redeemable convertible preferred stock, par value	$ 0.001	$ 0.001
Redeemable convertible preferred stock, shares authorized	11,449,515	11,449,515
Redeemable convertible preferred stock, shares issued	0	6,786,896
Redeemable convertible preferred stock, shares outstanding	0	6,786,896
Redeemable convertible preferred stock, liquidation value	$ 0	$ 60,150
Series C Redeemable Convertible Preferred Stock
Redeemable convertible preferred stock, par value	$ 0.001	$ 0.001
Redeemable convertible preferred stock, shares authorized	12,545,824	14,010,043
Redeemable convertible preferred stock, shares issued	0	7,377,480
Redeemable convertible preferred stock, shares outstanding	0	7,377,480
Redeemable convertible preferred stock, liquidation value	$ 0	$ 85,000