Quotation-direction extension, study C, 12 October 2026

Data: ECB series EXR.D.USD.EUR.SP00.A, USD per EUR.
Original snapshot retrieved 7 October 2026, NOT downloaded again for this extension.
Period: 4 January 2016 to 31 December 2025; 2,560 observations.
SHA-256: 12bda408fce288c0d9f68de03beffc6d89592a8fde37aff2d336b122baaddab3
The underlying ECB information is freely available from the ECB.
https://data-api.ecb.europa.eu/service/data/EXR/D.USD.EUR.SP00.A?startPeriod=2016-01-01&endPeriod=2025-12-31&format=csvdata
ECB reuse conditions: https://www.ecb.europa.eu/services/using-our-site/disclaimer/html/index.en.html
ECB reference-rate scope: https://www.ecb.europa.eu/stats/policy_and_exchange_rates/euro_reference_exchange_rates/html/index.en.html

Offline reproduction, Python 3.11 or newer (standard library only):
python research-analyze.py
python research-verify.py

Optional chart rendering: install matplotlib, then python research-plot.py.
Geometry and rendering stay in the plot script; text is provided in quotation-chart-labels.json.

Changes, reciprocals, drawdowns, tables and charts are our transformations.
They are NOT ECB observations or ECB-endorsed findings. Do not replace raw observations
with derived values, and retain source acknowledgement and the notice of free availability
if republishing for a fee. Python code may be reused under the included MIT license.
Reference rates are informational; ECB strongly discourages transaction use.
No executable bid/ask quotes, costs, leverage or account equity are modelled.
No strategy profitability or future-risk conclusion follows from these results.
AI tools assisted code and publication. Independent Decimal calculations verify arithmetic;
this is not independent human expert review.
