Bond price & duration

easyFinanceacceptance —~15 min

Implement bond_price_duration(face, coupon_rate, ytm, years, freq) for a plain fixed-coupon bond: freq coupons per year of face·coupon_rate/freq, principal at maturity, yield ytm compounded freq times a year. Return [price, macaulay_duration] — duration in years.

Price tells you what it costs; duration tells you how much it moves when yields shift by one percent. Return both rounded to 4 decimal places.

example 1

input

face=1000.0, coupon_rate=0.05, ytm=0.06, years=5, freq=1

output

[957.8764, 4.5347]

example 2

input

face=1000.0, coupon_rate=0.05, ytm=0.06, years=5, freq=2

output

[957.349, 4.4717]

constraints

face > 0
0 ≤ coupon_rate, ytm ≤ 0.2
1 ≤ years ≤ 30
freq ∈ {1, 2, 4}

teacher · 2 hints · the first is free

●solution.py· utf-8 · spaces:4

def bond_price_duration(face: float, coupon_rate: float, ytm: float, years: int, freq: int) -> list:
    """Return [price, macaulay duration in years], both rounded to 4 dp."""
    # TODO: coupons arrive `freq` times a year — periods, coupon and yield all scale
    n = years
    c = face * coupon_rate
    y = ytm
    price = 0.0
    weighted = 0.0
    for t in range(1, n + 1):
        cf = c + (face if t == n else 0.0)
        pv = cf / (1 + y) ** t
        price += pv
        weighted += t * pv
    return [round(price, 4), round(weighted / price, 4)]

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python 3.13 · pyodide

+ 6 hidden on submit

input · keyword arguments to bond_price_duration()

face=1000.0, coupon_rate=0.05, ytm=0.06, years=5, freq=1

expected

[957.8764, 4.5347]

the judge calls bond_price_duration() with exactly these inputs · outputs are compared to 6 decimal places

● standing bypython 3.13 in your browser · pyodide 0.28.3 · judged on the server to 6 dp⌘↵ run · ⌘⇧↵ submit

paper only · educational · not advice