Statistics of Price Movements of Amphastar Pharma (AMPH)

The price movements of Amphastar Pharma (ticker AMPH) are summarized in five ways:

• Table 1. Statistics of daily price changes using the closing prices
• Table 2. Statistics of daily price changes using the closing and opening prices
• Table 3 – 7. Statistics of daily price changes when AMPH opened with an increase of 1%, 2%, 3%, 4%, or more than 5%
• Table 8 – 10. Statistics of stock price changes in the 20 days after AMPH had a big price move
• Table 11. Statistics of daily price changes in the 20 days after AMPH moved 5% with twice the 30-day average volume

The statistics are calculated using AMPH's price data across 1,547 trading days from 2015 to 2020.

Table 1. Statistics of AMPH one-day price changes

In this table, the one-day price change is calculated using the closing price and the previous day's closing price.

In the past 1,547 trading days, 48.0% of the time (742 days), AMPH closed above the previous day's closing price. 47.2% of the time (729 days), it closed below the previous day's closing price. 4.9% of the time (75 days), it did not change.

Also see: VIX price movement study.

AMPH Price Change (%)	Number of Days	% of Total Sessions
16 – 17%	1	0.06%
13 – 14%	1	0.06%
12 – 13%	1	0.06%
11 – 12%	2	0.13%
10 – 11%	1	0.06%
9 – 10%	3	0.19%
8 – 9%	5	0.32%
7 – 8%	9	0.58%
6 – 7%	6	0.39%
5 – 6%	16	1.03%
4 – 5%	24	1.55%
3 – 4%	47	3.04%
2 – 3%	117	7.57%
1 – 2%	215	13.91%
0 – 1%	294	19.02%
0%	75	4.85%
0 – -1%	314	20.31%
-1 – -2%	179	11.58%
-2 – -3%	129	8.34%
-3 – -4%	62	4.01%
-4 – -5%	13	0.84%
-5 – -6%	17	1.10%
-6 – -7%	5	0.32%
-8 – -9%	2	0.13%
-9 – -10%	3	0.19%
-11 – -12%	1	0.06%
-14 – -15%	1	0.06%
-17 – -18%	1	0.06%
-22 – -23%	1	0.06%
-24 – -25%	1	0.06%

Table 2. Statistics of AMPH: Closing vs. Open

In this table, instead of using the closing price of the previous day, the opening price is used to calculate the one-day price change of AMPH.

48.0% of the time (743 days), AMPH closed above the opening price. 47.5% of the time (735 days), it closed below the opening price. 4.5% of the time (69 days), it closed where it started.

Closing - Open (%)	Number of Days	% of Total Sessions
14 – 15%	1	0.06%
11 – 12%	1	0.06%
10 – 11%	4	0.26%
8 – 9%	1	0.06%
7 – 8%	6	0.39%
6 – 7%	6	0.39%
5 – 6%	15	0.97%
4 – 5%	22	1.42%
3 – 4%	55	3.56%
2 – 3%	113	7.30%
1 – 2%	216	13.96%
0 – 1%	303	19.59%
0%	69	4.46%
0 – -1%	324	20.94%
-1 – -2%	187	12.09%
-2 – -3%	129	8.34%
-3 – -4%	50	3.23%
-4 – -5%	16	1.03%
-5 – -6%	14	0.90%
-6 – -7%	8	0.52%
-7 – -8%	2	0.13%
-8 – -9%	1	0.06%
-9 – -10%	1	0.06%
-12 – -13%	1	0.06%
-13 – -14%	1	0.06%
-20 – -21%	1	0.06%

Table 3. One-day performance when AMPH opened 5% higher than previous close

In the past 1,547 trading days, AMPH opened more than 5% higher than the previous day's closing price 6 times. Of these days, 66.7% (4 days) had closing prices above the opening price, and 33.3% (2 days) had closing prices below the opening price.

Closing - Open (%)	Number of Days	% of Total Sessions
5 – 6%	1	16.67%
1 – 2%	1	16.67%
0 – 1%	2	33.33%
0 – -1%	1	16.67%
-8 – -9%	1	16.67%

Table 4. Closing vs. open when AMPH opened 4–5% higher

On 5 days, AMPH opened 4–5% higher than the previous day's closing price. Of these days, 40.0% (2 days) had closing prices above the opening price, and 60.0% (3 days) had closing prices below the opening price.

Closing - Open (%)	Number of Days	% of Total Sessions
11 – 12%	1	20.00%
1 – 2%	1	20.00%
0 – -1%	1	20.00%
-3 – -4%	1	20.00%
-6 – -7%	1	20.00%

Table 5. Closing vs. open when AMPH open 3 – 4% higher

3 times AMPH opened 3 – 4% higher than the previous day's closing price. Among these days, 33.3% (1 days) closed above the opening price, 66.7% (2 days) closed below the opening price.

Closing - Open (%)	Number of Days	% of Total Sessions
4 – 5%	1	33.33%
0 – -1%	1	33.33%
-4 – -5%	1	33.33%

Table 6. Closing vs. open when AMPH open 2 – 3% higher

20 times AMPH opened 2 – 3% higher than the previous day's closing price. Among these days, 50.0% (10 days) closed above the opening price, 50.0% (10 days) closed below the opening price.

Closing - Open (%)	Number of Days	% of Total Sessions
5 – 6%	2	10.00%
4 – 5%	1	5.00%
3 – 4%	3	15.00%
2 – 3%	1	5.00%
1 – 2%	2	10.00%
0 – 1%	1	5.00%
0 – -1%	4	20.00%
-1 – -2%	1	5.00%
-2 – -3%	2	10.00%
-4 – -5%	1	5.00%
-5 – -6%	1	5.00%
-6 – -7%	1	5.00%

Table 7. Closing vs. open when AMPH open 1 – 2% higher

81 times AMPH opened 1 – 2% higher than the previous day's closing price. Among these days, 48.1% (39 days) closed above the opening price, 49.4% (40 days) closed below the opening price.

Closing - Open (%)	Number of Days	% of Total Sessions
10 – 11%	1	1.23%
8 – 9%	1	1.23%
7 – 8%	2	2.47%
6 – 7%	1	1.23%
5 – 6%	1	1.23%
4 – 5%	1	1.23%
3 – 4%	1	1.23%
2 – 3%	10	12.35%
1 – 2%	7	8.64%
0 – 1%	14	17.28%
0%	2	2.47%
0 – -1%	15	18.52%
-1 – -2%	9	11.11%
-2 – -3%	6	7.41%
-3 – -4%	4	4.94%
-4 – -5%	3	3.70%
-6 – -7%	2	2.47%
-7 – -8%	1	1.23%

Table 8. Periods when AMPH moved 15% or more

In this table, we track the price movements in the 20 days after AMPH had a one-day price change of at least 15%.

Date	Price Change	Price Change after 15% Move
Days after:		1	4	7	10	13	16	19
20161109	16.3%	-.5	2.4	3.4	.7	-.8	-4.1	1.8
20170314	-17.2%	10.1	17.0	12.4	19.9	18.9	16.4	19.3
20170221	-22.8%	-.6	10.7	6.6	5.4	3.0	-5.4	.5
20180510	-24.7%	1.9	9.4	13.3	13.2	10.0	10.2	14.8

Table 8a. AMPH average price changes following a 15% up day

Of the 1,547 trading days from 2015 to 2020, there were 1 days in which AMPH was up more than 15%. This table shows the average price changes over the 1 days.

Average Type	Average Price Change
Days after:	1	4	7	10	13	16	19
Avg for Change ≥ 15%	-.5	2.4	3.4	.7	-.8	-4.1	1.8

Table 8b. AMPH average price changes following a 15% down day

Of the 1,547 trading days from 2015 to 2020, there were 3 days in which AMPH was down more than -15%. This table shows the average price changes over the 3 days.

Average Type	Average Price Change
Days after:	1	4	7	10	13	16	19
Avg for Change ≥ -15%	3.8	12.3	10.8	12.8	10.6	7.1	11.5

Table 9. Periods when AMPH moved 10% or more

In this table, we track the price movements in the 20 days after AMPH had a one-day price change of at least 10%.

Date	Price Change	Price Change after 10% Move
Days after:		1	4	7	10	13	16	19
20161109	16.3%	-.5	2.4	3.4	.7	-.8	-4.1	1.8
20151113	13.3%	-.7	3.5	2.9	11.3	10.5	4.5	2.9
20160809	12%	1.2	2.4	8.7	13.7	8.3	5.8	3.4
20160920	11.8%	-1.7	-7.9	-11.4	-7.8	-8.3	-13.4	-15.1
20200317	11.2%	-11.9	-9.0	-.8	2.3	1.9	9.5	12.6
20170315	10%	-.6	.6	2.5	9.4	5.5	7.0	9.2
20200318	-11.8%	4.5	7.0	10.0	11.5	22.1	28.9	28.5
20190313	-14.4%	-.9	-.3	-2.5	-.8	1.8	3.0	1.3
20170314	-17.2%	10.1	17.0	12.4	19.9	18.9	16.4	19.3
20170221	-22.8%	-.6	10.7	6.6	5.4	3.0	-5.4	.5
20180510	-24.7%	1.9	9.4	13.3	13.2	10.0	10.2	14.8

Table 9a. AMPH average price changes following a 10% up day

Of the 1,547 trading days from 2015 to 2020, there were 6 days in which AMPH was up more than 10%. This table shows the average price changes over the 6 days.

Average Type	Average Price Change
Days after:	1	4	7	10	13	16	19
Avg for Change ≥ 10%	-2.4	-1.3	.9	4.9	2.9	1.6	2.5

Table 9b. AMPH average price changes following a 10% down day

Of the 1,547 trading days from 2015 to 2020, there were 5 days in which AMPH was down more than -10%. This table shows the average price changes over the 5 days.

Average Type	Average Price Change
Days after:	1	4	7	10	13	16	19
Avg for Change ≥ -10%	3.0	8.7	8.0	9.9	11.2	10.6	12.9

Table 10. Periods when AMPH moved 5% or more

In this table, we track the price movements in the 20 days after AMPH had a one-day price change of at least 5%.

Date	Price Change	Price Change after 5% Move
Days after:		1	4	7	10	13	16	19
20161109	16.3%	-.5	2.4	3.4	.7	-.8	-4.1	1.8
20151113	13.3%	-.7	3.5	2.9	11.3	10.5	4.5	2.9
20160809	12%	1.2	2.4	8.7	13.7	8.3	5.8	3.4
20160920	11.8%	-1.7	-7.9	-11.4	-7.8	-8.3	-13.4	-15.1
20200317	11.2%	-11.9	-9.0	-.8	2.3	1.9	9.5	12.6
20170315	10%	-.6	.6	2.5	9.4	5.5	7.0	9.2
20200326	9.7%	-2.2	-.9	8.6	14.5	14.2	13.6	14.0
20160510	9.6%	-1.3	3.6	9.9	19.2	21.2	22.0	23.7
20170526	9.6%	.0	.7	-.3	-.8	-4.4	-.2	4.0
20160315	8.6%	-4.6	-6.1	-6.0	-3.9	-.2	2.4	-2.2
20150930	8.4%	-1.4	-3.6	-2.6	-4.9	4.5	-5.7	-3.3
20150107	8.2%	-4.1	-7.3	-6.7	-8.5	-4.2	-2.1	-3.2
20180514	8.1%	-3.4	3.2	2.9	-.7	-2.0	3.3	3.4
20160520	8%	-2.4	.1	1.9	2.3	5.1	3.3	.0
20150908	7.7%	-4.0	.3	.3	-8.0	-20.6	-18.6	-19.3
20181108	7.5%	4.2	-2.8	-1.0	-3.4	-5.1	4.9	3.7
20200330	7.5%	-1.9	-2.2	5.0	8.0	5.8	5.9	10.6
20170926	7.4%	2.9	6.9	8.5	7.0	6.8	6.1	4.5
20200427	7.4%	-4.8	-6.5	-3.6	6.7	.0	4.4	3.1
20151028	7.3%	-3.2	1.9	6.4	3.5	13.7	18.5	17.8
20160628	7.2%	-3.3	-2.1	.2	4.3	4.8	5.1	-.4
20150826	7%	2.1	-1.8	-1.5	1.9	6.4	6.5	-2.4
20190808	7%	-2.0	-1.0	4.9	7.1	3.7	6.6	3.1
20200508	6.7%	2.1	-4.3	-.1	-1.3	.0	1.4	2.1
20181130	6.6%	3.6	.0	-2.2	-6.4	-4.5	-12.3	-8.1
20200408	6.5%	3.7	3.4	2.9	3.3	13.2	6.7	8.4
20160301	6.3%	1.8	3.4	-.6	13.6	3.9	6.4	3.7
20190104	6%	.5	6.3	6.1	6.3	9.5	6.1	10.3
20201005	6%	.3	5.5	3.6	3.4	2.2	-1.3	-2.7
20151102	5.8%	-1.3	3.1	.2	10.1	14.8	14.1	23.5
20160401	5.8%	1.5	1.7	-1.0	.2	1.7	.5	-1.1
20200310	5.7%	-.6	-15.3	-13.3	-11.1	-8.6	-7.4	1.4
20150513	5.6%	1.3	-2.1	-2.7	-.7	2.1	8.3	6.8
20171109	5.6%	-1.4	-5.1	-2.6	.5	-3.3	2.0	-2.6
20200406	5.6%	-4.5	5.5	3.7	6.4	6.1	9.7	7.8
20150911	5.5%	-.9	-.8	-9.1	-21.5	-19.5	-20.2	-21.2
20150223	5.4%	.4	3.3	6.9	10.5	14.1	11.8	8.8
20150116	5.3%	.0	-1.6	4.6	1.8	7.4	9.3	6.9
20151023	5.3%	-2.3	1.2	6.5	11.3	8.2	18.9	23.9
20160329	5.3%	-2.5	5.4	5.6	2.8	4.0	5.6	4.3
20150511	5.1%	-1.5	4.4	1.2	1.2	3.5	8.0	12.5
20170208	5.1%	.2	5.4	10.7	-15.0	-5.4	-8.9	-9.9
20170511	5%	2.2	-3.4	-2.1	-2.5	7.6	8.0	6.8
20190516	5%	-1.6	-5.0	-4.8	-10.8	-11.8	-9.7	-10.1
20200115	5%	.2	-.2	-1.9	-.3	-4.5	-.4	-.3
20151020	-5%	-2.2	-2.2	1.3	6.6	11.4	8.3	19.0
20160111	-5%	1.2	.1	2.0	-1.3	-3.2	-5.9	-10.0
20170111	-5%	.5	-4.3	-8.2	-7.7	-11.8	-8.2	-8.3
20181114	-5%	3.9	-.3	.1	2.0	11.8	7.9	5.6
20200309	-5%	5.7	-2.5	-12.2	-9.4	-1.2	1.9	1.5
20161121	-5.1%	-1.2	2.6	.8	3.3	-.7	-1.1	4.4
20200320	-5.1%	4.2	13.6	17.2	16.7	25.4	29.0	26.3
20170321	-5.3%	.7	5.6	9.0	5.8	8.1	9.3	10.1
20160824	-5.4%	-.4	.8	-3.8	-1.4	-4.7	-3.3	10.2
20150824	-5.5%	-2.9	2.8	4.4	2.4	5.8	10.9	13.1
20160922	-5.5%	1.6	-.9	-2.1	-3.3	-2.9	-8.9	-8.4
20150115	-5.6%	5.4	3.4	8.2	10.6	9.4	12.7	14.1
20160229	-5.7%	6.4	6.9	6.7	11.2	7.6	16.7	13.6
20191111	-5.7%	1.6	-.7	4.2	8.0	7.5	9.7	9.1
20161207	-5.8%	1.6	1.2	6.9	2.7	4.0	-6.5	-5.9
20150325	-5.9%	3.7	3.7	3.7	4.6	5.7	6.2	5.5
20150921	-5.9%	-4.7	-17.7	-15.7	-16.4	-17.4	-20.5	-14.1
20171106	-6%	-.4	3.2	-.6	2.0	5.2	1.2	6.7
20180205	-6.2%	1.8	6.8	8.9	9.0	9.3	10.5	6.4
20160317	-6.6%	2.7	5.2	2.5	5.9	10.5	12.6	12.5
20190513	-6.8%	.6	5.0	1.4	1.6	-4.8	-5.9	-3.7
20161103	-6.9%	2.1	20.7	20.8	26.8	16.9	21.5	19.3
20200316	-8.1%	11.3	-2.8	.5	16.0	13.4	14.4	26.4
20150925	-8.2%	-3.8	1.1	-1.1	-.1	-2.5	7.2	-3.3
20161227	-9.1%	-.2	-.8	.7	-2.2	-7.6	-10.8	-15.1
20200228	-9.2%	3.0	2.1	.0	-7.8	-17.0	-14.3	-6.6
20200312	-9.3%	2.3	-7.9	-4.9	3.7	7.0	6.6	14.5
20200318	-11.8%	4.5	7.0	10.0	11.5	22.1	28.9	28.5
20190313	-14.4%	-.9	-.3	-2.5	-.8	1.8	3.0	1.3
20170314	-17.2%	10.1	17.0	12.4	19.9	18.9	16.4	19.3
20170221	-22.8%	-.6	10.7	6.6	5.4	3.0	-5.4	.5
20180510	-24.7%	1.9	9.4	13.3	13.2	10.0	10.2	14.8

Table 10a. AMPH average price changes following a 5% up day

Of the 1,547 trading days from 2015 to 2020, there were 45 days in which AMPH was up more than 5%. This table shows the average price changes over the 45 days.

Average Type	Average Price Change
Days after:	1	4	7	10	13	16	19
Avg for Change ≥ 5%	-.9	-.3	1.0	1.7	2.4	3.2	3.2

Table 10b. AMPH average price changes following a 5% down day

Of the 1,547 trading days from 2015 to 2020, there were 32 days in which AMPH was down more than -5%. This table shows the average price changes over the 32 days.

Average Type	Average Price Change
Days after:	1	4	7	10	13	16	19
Avg for Change ≥ -5%	1.9	2.8	2.8	4.3	4.4	4.8	6.5

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Also see: VIX price movement study.