schwab 里对用spx hedge 的介绍和例子。居安思危，大佬们多谈谈哈

https://www.schwab.com/learn/story/how-to-hedge-your-portfolio

用2% 仓位做保护, 只是理论，3 个月是期权 time decay 很厉害

Portfolio value at expiration of three-month SPX put options

Portfolio value at expiration of three-month SPX put options

SPX percentage change	Unhedged portfolio percentage change	SPX value	Value of two SPX 5,425 puts	Portfolio value (no hedge)	Portfolio value with SPX puts	Hedged portfolio percentage change
+5%	+5%	5,696	0	$1,050,000	$1,030,00	+3.00%
0%	0%	5,425	0	$1,000,000	$980,000	-2.00%
-5%	-5%	5,153	$54,400	$950,000	$1,004,400	+0.44%
-10%	-10%	4,882	$108,600	$900,000	$1,008,600	+0.86%
-15%	-15%	4,611	$162,800	$850,000	$1,012,800	+1.28%
-20%	-20%	4,340	$217,000	$800,000	$1,017,000	+1.70%