Discrepancy in quantopian input data sets???

Quantopoian is showing the percentage increase in stock NTN is 30000% for the time period 10/16/2013 to 10/16/2016.

Below is the data given out by research:

    open_price  high    low close_price volume  price
2013-10-16 00:00:00+00:00   0.2300  0.2300  0.2050  0.2240  117726.0    0.2240
2013-10-17 00:00:00+00:00   0.2350  0.2350  0.2200  0.2200  45918.0 0.2200
2013-10-18 00:00:00+00:00   0.2200  0.2200  0.2050  0.2120  52622.0 0.2120
2013-10-21 00:00:00+00:00   0.2210  0.2300  0.2200  0.2300  93000.0 0.2300
2013-10-22 00:00:00+00:00   0.2340  0.2340  0.2200  0.2270  60230.0 0.2270
2013-10-23 00:00:00+00:00   0.2200  0.2330  0.2150  0.2320  63736.0 0.2320
2013-10-24 00:00:00+00:00   0.2350  0.2350  0.2300  0.2350  52176.0 0.2350
2013-10-25 00:00:00+00:00   0.2350  0.3220  0.2300  0.3220  310078.0    0.3220
2013-10-28 00:00:00+00:00   0.3500  0.3500  0.2150  0.2700  336384.0    0.2700
2013-10-29 00:00:00+00:00   0.2650  0.2750  0.2460  0.2550  204824.0    0.2550
2013-10-30 00:00:00+00:00   0.2680  0.2680  0.2400  0.2490  103430.0    0.2490
2013-10-31 00:00:00+00:00   0.2500  0.2500  0.2170  0.2410  138990.0    0.2410
2013-11-01 00:00:00+00:00   0.2490  0.2500  0.2400  0.2450  51400.0 0.2450
2013-11-04 00:00:00+00:00   0.2500  0.2780  0.2500  0.2600  69058.0 0.2600
2013-11-05 00:00:00+00:00   0.2700  0.2750  0.2500  0.2610  54560.0 0.2610
2013-11-06 00:00:00+00:00   0.2700  0.2700  0.2550  0.2700  88940.0 0.2700
2013-11-07 00:00:00+00:00   0.2600  0.2700  0.2500  0.2700  115800.0    0.2700
2013-11-08 00:00:00+00:00   0.2500  0.3000  0.2500  0.2940  257170.0    0.2940
2013-11-11 00:00:00+00:00   0.2840  0.2840  0.2710  0.2750  73752.0 0.2750
2013-11-12 00:00:00+00:00   0.2750  0.2850  0.2750  0.2850  244174.0    0.2850
2013-11-13 00:00:00+00:00   0.2730  0.2750  0.2660  0.2680  121544.0    0.2680
2013-11-14 00:00:00+00:00   0.2750  0.3080  0.2500  0.2900  1063710.0   0.2900
2013-11-15 00:00:00+00:00   0.3000  0.3000  0.2700  0.2950  776546.0    0.2950
2013-11-18 00:00:00+00:00   0.2800  0.2950  0.2800  0.2900  334010.0    0.2900
2013-11-19 00:00:00+00:00   0.2920  0.3250  0.2900  0.3250  241288.0    0.3250
2013-11-20 00:00:00+00:00   0.3250  0.3870  0.3250  0.3400  249268.0    0.3400
2013-11-21 00:00:00+00:00   0.3400  0.3400  0.3150  0.3250  209036.0    0.3250
2013-11-22 00:00:00+00:00   0.3280  0.3700  0.3230  0.3590  384006.0    0.3590
2013-11-25 00:00:00+00:00   0.3800  0.4180  0.3800  0.3820  1160070.0   0.3820
2013-11-26 00:00:00+00:00   0.3800  0.3890  0.3680  0.3890  233884.0    0.3890
... ... ... ... ... ... ...
2016-09-02 00:00:00+00:00   7.0500  7.3700  6.8000  7.1500  4712.0  7.1500
2016-09-06 00:00:00+00:00   7.2800  7.4900  6.7300  6.7300  8517.0  6.7300
2016-09-07 00:00:00+00:00   7.2000  7.2000  6.6500  6.6500  3441.0  6.6500
2016-09-08 00:00:00+00:00   6.6500  7.0100  6.4500  6.5900  6110.0  6.5900
2016-09-09 00:00:00+00:00   6.5400  7.4100  6.4200  7.4100  16017.0 7.4100
2016-09-12 00:00:00+00:00   7.2600  7.4411  6.7500  7.0200  10714.0 7.0200
2016-09-13 00:00:00+00:00   7.1200  7.4700  6.9201  7.1400  3576.0  7.1400
2016-09-14 00:00:00+00:00   7.2700  7.5000  7.0510  7.3300  7137.0  7.3300
2016-09-15 00:00:00+00:00   7.4100  7.4200  7.1900  7.3600  4766.0  7.3600
2016-09-16 00:00:00+00:00   7.3400  7.5000  7.0200  7.5000  8113.0  7.5000
2016-09-19 00:00:00+00:00   7.4700  7.7900  7.4100  7.7900  6690.0  7.7900
2016-09-20 00:00:00+00:00   7.7300  7.8175  7.2700  7.5400  3534.0  7.5400
2016-09-21 00:00:00+00:00   7.3100  7.8900  7.3000  7.4200  1742.0  7.4200
2016-09-22 00:00:00+00:00   7.3546  7.6000  6.7500  7.3800  31792.0 7.3800
2016-09-23 00:00:00+00:00   7.4100  7.6600  7.1800  7.4500  25998.0 7.4500
2016-09-26 00:00:00+00:00   7.5000  7.6100  7.1700  7.6100  7914.0  7.6100
2016-09-27 00:00:00+00:00   7.4200  7.5000  7.1600  7.2700  6741.0  7.2700
2016-09-28 00:00:00+00:00   6.9400  7.3300  6.7601  6.9500  11058.0 6.9500
2016-09-29 00:00:00+00:00   7.1600  7.3100  6.7000  7.0000  15644.0 7.0000
2016-09-30 00:00:00+00:00   6.8100  7.0990  6.7701  6.9501  6013.0  6.9501
2016-10-03 00:00:00+00:00   6.9400  6.9800  6.6100  6.7201  9492.0  6.7201
2016-10-04 00:00:00+00:00   6.7200  6.7500  6.6600  6.6700  1144.0  6.6700
2016-10-05 00:00:00+00:00   6.5300  6.7690  6.5300  6.7400  3083.0  6.7400
2016-10-06 00:00:00+00:00   NaN NaN NaN NaN NaN NaN
2016-10-07 00:00:00+00:00   6.6000  6.8100  6.5200  6.6000  4772.0  6.6000
2016-10-10 00:00:00+00:00   6.5100  6.5100  6.5100  6.5100  167.0   6.5100
2016-10-11 00:00:00+00:00   6.5300  6.6000  6.5300  6.5600  3030.0  6.5600
2016-10-12 00:00:00+00:00   6.6000  6.6840  6.5201  6.6200  11488.0 6.6200
2016-10-13 00:00:00+00:00   6.5300  6.7700  6.5200  6.6000  301.0   6.6000
2016-10-14 00:00:00+00:00   6.5200  7.0000  6.5200  6.8000  15253.0 6.8000


% Increase is 6.8/0.2240 = 30000 percent increase.

But actually for the three years time period considered the stock is down about 56% for the three years.

Why is this much of discrepancy... I am about to scratch off my algo, just checked where I invested large amount of my money found this, my algo supposed to look for uptrend but actually this is downtrend.

Is this the only stock or there are many others..

Anyone help me with this am I missing something??

1 response

It looks like our datasource is missing a 50:1 split from 6/17/2016. We've got a fix for that coming in.

Data errors are always present in financial data; I'm sure we haven't found them all. The good news is that with thousands of people looking at our data, we get error reports and clean them up. It makes for a pretty high-quality data source because of the level of review.

Sorry for the confusion.

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