Disclaimer: this is not investment advice. Do not make investment decisions based off my Internet comments.Let's say Company X has 9,000 shares of common stock outstanding. It raises $1 million at a $10 million post-money valuation with a 1x non-participating liquidation preference. Its cap table is thus 1,000 shares of Series A preferred stock on top of 9,000 shares of common.
It then raises $10 million at a $50 million valuation with similar preference terms. Its cap table is now 2,500 shares of Series B preferred stock on top of 1,000 shares of Series A preferred stock on top of 9,000 shares of common.
Let's contemplate a $100 million exit. Everyone converts to common at $100 million / 12,500 shares, or $8,000 per share. Series A bought at $1,000 and thus sees an 8x return; Series B bought at $4,000 and thus sees 2x.
Let's contemplate a $50 million exit. Everyone converts at $50 million / 12,500 shares, or $4,000 per share. Series A gets 4x; B comes out flat.
Let's contemplate a $25 million exit. Series B does not convert. Instead, it demands its 1x liquidation preference and gets $10 million. This leaves $15 million on the table, or $1,500 per share. Series A converts and sees its 1.5x return; B comes out flat.
Let's contemplate a $15 million exit. Series B does not convert and gets its $10 million. This leaves $5 million on the table, or $500 per share. Series A does not convert and demands its $1 million. Series A and B come out flat; common gets $4 million / 9,000 shares, or about $444.
Let's contemplate a $10 million exit. Series B gets its $10 million and comes out flat; everyone else gets screwed.
Let's contemplate a Theranos exit. Everyone gets screwed. Turtleneck doesn't go to jail.
TL; DR Later stages are least volatile. They get screwed last, but also see upside last. Lower rungs' returns pay for this safety.