1.) What does "Pro Forma" mean on the right most column? Is that different from the regular 2018 in the middle column and those numbers, specifically for the stockholders equity part?

2.) What does the negative stockholder equity indicate? Is that a red flag for an investor?

Pro Fonma December 31, ASSETS Current assets Cash and cash equivalents Marketable securities Accounts receivable net of allowances of $2,408 and $3,097 as of $ 71.468 640,160 122,509 505.304 136,597 38,734 386,959 87.255 152,257 9,037 11,650 221,932 39,607 889,352 81,512 145,203 14,071 11,724 10,869 S 1,152,731 December 31, 2017 and 2018, respectively Prepaid expenses and other current assets Total current assets Property and equipment, net Operating lease right-of-use assets Goodwill and intangible assets, net Restricted cash Other assets Total assets LIABILITIES, REDEEMABLE CONVERTIBLE PREFERRED STOCK AND S 1,173,045 STOCKHOLDERS EQUITY (DEFICIT Current labilities Accounts payable S 15,428 S 22,169 64.374 79,802 12.035 Accrued expenses and other current liabiaties 6,258 361,316 108,427 151,395 22,073 281,895 Total current liabilities Operating lease liabilities Other liabilities Total liabities Commitments and contingencies Redeemable convertible preferred stock, $0.00001 par value, 928,676 shares 17.139 254,110 authorized: 308,373 shares issued and outstanding as of December 31, 2017 and 2018, aggregate liquidation preference of S1,466,902 as of December 31, 2017 and 2018; no shares authorized, issued and outstanding, pro forma (unaudited) 1,465,399 1,465,399 Stockholders' equity (deficit) Common stock, $0.00001 par value, 1,932,500 shares authorized; 126,771 and 127,298 shares issued and outstanding as of December 31, 2017 and 2018 454,344 shares issued and outstanding, pro forma (unaudited) Additional paid-in capital Accumulated other comprehensive loss Accumulated deficit 252,212 845,355) (546.464) (594.563) 600.712 2,333,009 (1.421) 1.730,880) 236.682 (766) 82.381) (1,421) Total stockholders' equity (deficit) Total liabilities, redeemable convertible preferred stock, and stockholders' equity (deficit) 1,173,045 S 1,152,731 1,152,731