Bonds — Swiss Confederation Bond Yields

The Bonds class provides Swiss Confederation government bond yields, sourced from the Swiss National Bank (monthly data, 13 maturities).

from swiss_finance import Bonds

Available maturities

13 standard maturities are supported:

1y, 2y, 3y, 4y, 5y, 6y, 7y, 8y, 9y, 10y, 15y, 20y, 30y

`Bonds.list_maturities`

Bonds.list_maturities() -> list

List all available bond maturities.

Example:

Bonds.list_maturities()
# ['1y', '2y', '3y', '4y', '5y', '6y', '7y', '8y', '9y', '10y', '15y', '20y', '30y']

`Bonds.get_yield`

Bonds.get_yield(maturity='10y', provider='snb_bonds') -> float

Get the latest yield for a given Swiss Confederation bond maturity.

Parameters:

Parameter	Type	Description
`maturity`	`str`	Bond maturity (e.g. `'10y'`, `'2y'`, `'30y'`). Default: `'10y'`
`provider`	`str`	Data provider (default: `'snb_bonds'`)

Returns: Yield in percent (e.g. 0.85 means 0.85%).

Raises: ValueError if maturity unknown, SNBAPIError if API fails.

Example:

yield_10y = Bonds.get_yield("10y")
print(f"10y Confederation bond: {yield_10y:.2f}%")
# 10y Confederation bond: 0.85%

yield_2y = Bonds.get_yield("2y")
yield_30y = Bonds.get_yield("30y")
print(f"2y: {yield_2y:.2f}%  |  30y: {yield_30y:.2f}%")
# 2y: 0.48%  |  30y: 1.12%

# Spread 10y minus 2y
spread = yield_10y - yield_2y
print(f"10y-2y spread: {spread:.2f}%")
# 10y-2y spread: 0.37%

`Bonds.get_yield_curve`

Bonds.get_yield_curve(provider='snb_bonds') -> pd.DataFrame

Get the latest Swiss Confederation yield curve (all maturities, single row).

Returns: DataFrame with one row (latest date) and one column per maturity (1y, 2y, …, 30y). Values in percent.

Raises: SNBAPIError if API fails.

Example:

curve = Bonds.get_yield_curve()
print(curve.T)

       2025-12-01
1y         0.42
2y         0.48
3y         0.52
4y         0.58
5y         0.63
6y         0.68
7y         0.72
8y         0.76
9y         0.80
10y        0.85
15y        0.98
20y        1.05
30y        1.12

# Plot the yield curve
import matplotlib.pyplot as plt

curve = Bonds.get_yield_curve()
maturities = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 30]
yields = curve.iloc[0].values

plt.figure(figsize=(10, 5))
plt.plot(maturities, yields, marker="o", color="red")
plt.xlabel("Maturity (years)")
plt.ylabel("Yield (%)")
plt.title(f"Swiss Confederation Yield Curve — {curve.index[0].date()}")
plt.grid(True, alpha=0.3)
plt.tight_layout()
plt.show()

`Bonds.get_historical_yields`

Bonds.get_historical_yields(
    maturity=None,
    start=None,
    end=None,
    provider='snb_bonds'
) -> pd.DataFrame

Get historical Swiss Confederation bond yields.

Parameters:

Parameter	Type	Description
`maturity`	`str`	Bond maturity (e.g. `'10y'`). If `None`, returns all maturities
`start`	`str`	Start date `YYYY-MM-DD` (optional)
`end`	`str`	End date `YYYY-MM-DD` (optional)
`provider`	`str`	Data provider (default: `'snb_bonds'`)

Returns: DataFrame with DatetimeIndex and one column per maturity (or just the requested maturity).

Raises: ValueError if maturity unknown or start > end, SNBAPIError.

Example:

# Single maturity
hist_10y = Bonds.get_historical_yields(maturity="10y", start="2020-01-01")
print(hist_10y.head())

              10y
date
2020-01-01   -0.52
2020-02-01   -0.67
2020-03-01   -0.37
2020-04-01   -0.48
2020-05-01   -0.43

# All maturities
hist_all = Bonds.get_historical_yields(start="2023-01-01")
print(hist_all.columns.tolist())
# ['1y', '2y', '3y', '4y', '5y', '6y', '7y', '8y', '9y', '10y', '15y', '20y', '30y']

print(hist_all.tail(3))

               1y    2y    3y   ...   10y   20y   30y
date
2025-10-01   0.38  0.44  0.49  ...  0.82  1.02  1.10
2025-11-01   0.40  0.46  0.51  ...  0.84  1.04  1.11
2025-12-01   0.42  0.48  0.52  ...  0.85  1.05  1.12

# Plot 10y yield history
import matplotlib.pyplot as plt

hist = Bonds.get_historical_yields(maturity="10y", start="2015-01-01")
hist.plot(title="Swiss 10y Confederation Bond Yield", figsize=(12, 5))
plt.axhline(0, color="red", linewidth=0.7, linestyle="--")
plt.ylabel("Yield (%)")
plt.tight_layout()
plt.show()

Data source

Bond yields are sourced from the SNB data portal (data.snb.ch), cube rendoblid. Data is monthly. The SNB provides spot interest rates for Swiss Confederation bond issues across 13 standard maturities.