# Yahoo data meaning of “close” and “adjusted close”

When there's a 2-for-1 stock split,

• the number of shares doubles, while
• the value of the stock halves

For symbol 2154 on the Tokyo Stock Exchange, there was such a 2-for-1 split on 2016/3/29.

However when looking at csv data download from Yahoo, I see the "adjusted close" doubling (not halving), while the unadjusted "Close", as well as Open, High, Low, barely move.

Here's an excerpt:

       2154     Open     High      Low    Close  Volume  Adj Close
-------------------------------------------------------------------
2016-03-30  1576.00  1602.00  1530.00  1530.00   63600    1503.08
2016-03-29  1455.00  1620.00  1455.00  1551.00   86700    1523.71
2016-03-28  1450.00  1452.50  1425.50  1450.00   29000     712.24
2016-03-25  1469.50  1475.00  1438.50  1442.50   23200     708.56


How does this all add up? What was the actual price used on 2016/03/28 when 2154 was traded? Somewhere around 1450? Or 700? Or 2900?

I just looked at another set of Yahoo data for 2170 on the Tokyo Stock Exchange, which had a 100-for-1 split on 2014/3/27, and here everything looks as I would have expected.

       2170        Open        High         Low       Close  Volume  Adj Close
-------------------------------------------------------------------------------
2014-03-28      230.00      230.00      219.00      230.00   74700   190.4468
2014-03-27      224.00      229.00      191.00      225.00  119300   186.3067
2014-03-26    23500.00    23500.00    22000.00  22339.9994  181700   184.2366
2014-03-25  23739.9994  24080.0003  22810.0006  23230.0003  278800   191.5764