[大昌期貨]何謂正價差與逆價差？ https://dcnf-futures.webnode.tw/news/%e5%a4%a7%e6%98%8c%e6%9c%9f%e8%b2%a8-%e4%bd%95%e8%ac%82%e6%ad%a3%e5%83%b9%e5%b7%ae%e8%88%87%e9%80%86%e5%83%b9%e5%b7%ae%ef%bc%9f/
