===== qna =====
==== treasury bills vs. notes vs. bonds ====
??? What is the difference between Treasury bills, notes and bonds?
!!!

^ ^ Treasury Bills ^ Treasury Notes ^ Treasury Bonds ^
| term | short-term | short or medium-term | long-term |
| mature in | one year or less | 2, 3, 5, 7, or 10 years | 20 or 30 years |

Ref:- https://www.treasurydirect.gov/marketable-securities/understanding-pricing/

===== methodology related =====
==== high rate vs. investment rate ====
??? What is the difference between "high rate" and "investment rate" in https://www.treasurydirect.gov/auctions/announcements-data-results/?

!!! For bills not more than one half-year to maturity
<code>
high_rate = ((100-P) / 100) * (360 / r)
investment_rate = ((100-P) / P) * (y / r)
</code>
Where P is the price, r is days to maturity, y is days in year (365 in normal year, 366 in leap year)

Ref:-
  * https://www.treasurydirect.gov/instit/annceresult/press/preanre/2004/ofcalc6decbill.pdf
  * https://www.bogleheads.org/forum/viewtopic.php?t=252066

For example, on 2023-01-19, https://www.treasurydirect.gov/auctions/announcements-data-results/ showed

^ Security Term ^ CUSIP ^ Issue Date ^ Maturity Date ^ High Rate ^ Investment Rate ^
| 4-week | [[https://www.treasurydirect.gov/auctions/auction-query/?cusip=912796Y60 | 912796Y60]] | 01/24/2023 | 02/21/2023 | 4.480% | 4.558% |

Clicking on the CUSIP showed

^ CUSIP ^ Security Type ^ Security Term ^ Auction Date ^ Issue Date ^ Maturity Date ^ Price per $100 ^
| 912796Y60 | Bill | 4-Week | 01/19/2023 | 01/24/2023 | 02/21/2023 | 99.651556 |

<code>
$ ipython
Python 3.10.8 | packaged by conda-forge | (main, Nov 24 2022, 14:07:00) [MSC v.1916 64 bit (AMD64)]
IPython 8.7.0 -- An enhanced Interactive Python. Type '?' for help.

In [1]:
P = 99.651556; r = 28; y = 365

In [2]:
high_rate = ((100-P) / 100) * (360 / r)

In [3]:
high_rate
Out[3]:
0.04479994285714294

In [4]:
round(high_rate * 100, 3)
Out[4]:
4.48

In [5]:
investment_rate = ((100-P) / P) * (y / r)

In [6]:
investment_rate
Out[6]:
0.04558098850530179

In [7]:
round(investment_rate * 100, 3)
Out[7]:
4.558
</code>

===== dummy =====
==== Highlights from https://www.treasurydirect.gov/forms/sec009.pdf ====
  *  bill, note, bond, FRN, and TIPS
  * FRNs = Floating rate notes
  * TIPS = Treasury inflation-protected securities
  * 4-week, 8-week, 13-week, 26-week, and 52week bills
  * For more about entity accounts, see "User Guide 292" - https://www.treasurydirect.gov/indiv/help/treasurydirect-help/user-guide/291-300/#id-user-guide-292-263212


==== links I came across ====
  * https://www.treasurydirect.gov/auctions/how-auctions-work/ - How auctions work
  * https://www.treasurydirect.gov/forms/sec009.pdf - Investing Directly With the U.S. Treasury (FS Publication 009) is an introductory publication.
  * https://www.treasurydirect.gov/indiv/help/treasurydirect-help/user-guide/291-300/ - User guide sections 291 through 300