Credit quality constant kyun rakhte hain? Kyunki ek bond ki yield reflect karti hai dono — borrower kitna risky hai aur aap kitne time ke liye lend kar rahe ho. "Price of time" study karne ke liye, hume "price of default risk" hatani padti hai. Government bonds ko (almost) risk-free treat kiya jaata hai, toh jo bachta hai woh pure time hai.
Ek bond fixed cash flows ka promise karta hai. Uski aaj ki price un cash flows ki present value hoti hai. Yield to maturity (y) woh single discount rate hai jo present value ko market price ke equal banata hai.
Ek zero-coupon bond ke liye jo face value F pay karta hai n saalon mein price P par:
P=(1+y)nF
Yeh form kyun? Agar 1aajnsaalonmein(1+y)^nbanjaatahai,tohnsaalonmeinmilnewalaFaajsirfF/(1+y)^n$ worth hai. Hum invert karte hain woh rate find karne ke liye jo market charge kar rahi hai:
y=(PF)1/n−1
Yeh step kyun? Hum F ko P se divide karte hain total growth factor paane ke liye, n-th root lete hain per-year growth factor paane ke liye, phir 1 subtract karte hain factor ko rate mein convert karne ke liye.
Term (liquidity) premium: 30 saalon ke liye paisa lock karna riskier hai (inflation surprises, opportunity cost), toh investors extra reward maangte hain. KYU: apna cash easily wapas nahi le sakte, toh tum inconvenience ke liye charge karte ho.
Growth/inflation expectations: ek healthy economy expect karti hai ki future rates badhenge, toh long bonds ko compete karne ke liye zyada offer karna padta hai.
Inverted curve ka matlab hai ki market expect karti hai ki central bank future mein short-term rates cut karega — aur cut karne ki wajah sirf ek hoti hai — slowing economy. Investors, recession se darte hue, aaj ke long rates lock karne ki koshish karte hain, long-bond prices upar bid karte hain aur long yields short yields se neeche aa jaate hain.
Recall Feynman: ek 12-saal ke bachche ko explain karo
Socho tum apne dost ko paisa udhaar de rahe ho. Agar woh kal wapas kare, toh tum ek chota sa shukriya chahte ho. Agar woh 10 saal tak rakhta hai, toh tum bada shukriya chahte ho kyunki tum zyada wait kiya aur kuch bhi ho sakta tha. Yield curve sirf ek chart hai ki "kitna bada shukriya" tumhe milta hai alag-alag time wait karne ke liye. Usually zyada wait = bada shukriya (upar jaati line). Lekin agar achanak sab sochne lage ki future scary lagta hai, toh woh abhi long term ke liye lend karne ki rush karte hain, aur long-term shukriya actually chhota ho jaata hai short-term wale se — woh ulti line ("inversion") ek weather warning ki tarah hai ki ek toofan (recession) aa sakta hai.