EOD Data is free or low cost... ie. eoddata.com, yahoo etc.
Problem is many options trade thinly and last prints can be days old.
You also need ohlc and an adjusted close for splits/dividends etc.
Most services are based on last print which yields substantially different results than a tick accurate extraction based on bid/ask quotes. Makes a significant difference for intraday analysis but may not be relevant for eod type analysis.
We build out and track ohlc on bid/ask and VWAP on trades between quote ticks. Found this to be a much more reliable data scheme as it accurately reflects "executable" market conditions. No reliable 3rd party for this type of data so we build it in house.
I pulled just the EOD equities data from 2008 to present.
The DB is just over 12 million records, 24K distinct symbols and 2GB in size.
The corresponding splits/divs/symbol changes are relatively small but are vital for historic analysis.
Easily manageable in matlab and excel either loading symbol sets or running queries against the indexed tables either on disk or loaded in memory.
Example may be something like a dispersion algo analyzing SPY against its composites. 501 symbols x 5 years of EOD results in an excel workbook of 550,000 rows x 8 columns. Near instantaneous result sets using Autofilters in excel... 80Mb workbook. High Resolution Data Repository >>> Extract Focus Instrument Sets EOD Data >>> Load into Analysis Engine. This style of processing optimizes well for speed, performance and reduces the working data size.
Quote from derTrader:
Any chance to get historical options EOD data cheaper?