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次按 - Subprime mortgage
A subprime mortgage is one that’s normally issued to borrowers
with low credit ratings. A prime conventional mortgage isn’t offered, because the lender views the borrower as having a greater-than-average risk of defaulting on the loan.
https://www.investopedia.com/terms/s/subprime_mortgage.asp
次按同一般prime mortgage 唔同就係 borrower 個credit rating 比 正常人低 但係同prime mortgage 都一樣需要抵押層樓
subprime mortgage 既borrower 因為poor credit rating
需要支付比 prime mortgage 更加高既interest rate
開始銀行就發現 如果將d prime mortgage 同埋 subprime mortgage 撈埋一齊之後個return 會高左 但係credit rating 依然定義為優質
呢一點非常吸引投資者去投資 同埋佢地參與到只有銀行參與mortgage market
呢樣野叫 Mortgage back securities (MBS) 係mortgage securitization 之下既產物
係另一方面因為銀行賣左d mortgage loan 出街可以write off 個risk exposure 同埋可以賺到個transaction fee
銀行收番d資金之後 又可以繼續借比新既人 結果成個mortgage market 開始急速發展
銀行都開始發現無論個MBS 撈好多 subprime mortgage 落去, 隻MBS rating 都唔會大跌, 因為好多人借錢買樓 樓價都因為咁上升(就算borrower default 還唔起錢 拎佢collateral去拍賣 investor 都收得番條數) 所以感覺MBS 穩賺不賠
同時銀行開始借比d credit rating 更加低既人 甚至無收入 只有呼吸就借
因為無論點呢d MBS 一日之內就會有investor 買走 對銀行黎講無risk
之後既發展同the big short 一樣
Michael Burry 同其他the big short 主角一樣 發現其實d MBS唔係想像中咁rock solid, 同埋個rating 應該比宜加更低, 跟住就去銀行買Credit Default Swap (CDS) 去賭 MBS 既價錢會因為default rate 上升而跌
如同套戲一樣 d ibanker 正情當佢地係offer free money 因為佢覺得MBS跟本唔會跌 所以銀行自己都無去hedge 呢個position 直接同呢班痴線佬對賭
然後銀行又將d CDS 同 MBS 撈埋一齊賣 呢樣野叫 Collateralized Debt Obligation (CDO) e.g. "雷曼債" 因為咁樣個yield 更高 rating 又一樣好 吸引好多投資者去買. 銀行又可以賺到transaction fee 對佢自己個risk都可以減低. 然後再有d咩 CDO square, Synthetic CDO 呢d 各式各樣既derivative. 因為呢d derivative (CDO, CDO square, Synthetic CDO) scale up左成個mortgage market 有幾十至一百倍. 大家都"賭" 大家還到錢 樓市唔會跌
跟主經濟開始唔掂, 大家還唔起錢, 比人收樓, 大量銀主盤, 樓價大跌, d MBS 價格大跌 導致到銀行要賠天文數字比Michael Burry 班痴線佬, 大家買個d 雷曼債都變0 因為佢既價值係CDS 收番黎既錢
你係無錯 因為次按投資者係買左 subprime mortgage 既derivative 所以係無任何抵押品
但係 subprime mortgage 本身係有層樓做抵押