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Side-by-side financial comparison of Amphastar Pharmaceuticals, Inc. (AMPH) and RAMBUS INC (RMBS). Click either name above to swap in a different company.

Amphastar Pharmaceuticals, Inc. is the larger business by last-quarter revenue ($183.1M vs $180.2M, roughly 1.0× RAMBUS INC). RAMBUS INC runs the higher net margin — 33.2% vs 13.3%, a 19.9% gap on every dollar of revenue. On growth, RAMBUS INC posted the faster year-over-year revenue change (8.1% vs -1.8%). Over the past eight quarters, RAMBUS INC's revenue compounded faster (16.8% CAGR vs 3.2%).

Amphastar Pharmaceuticals is a publicly traded American speciality pharmaceutical company. It was incorporated in May 2004 and primarily develops, manufactures, and sells inhalation and intranasal products.

Rambus Inc. is an American technology company that designs, develops and licenses chip interface technologies and architectures that are used in digital electronics products. The company, founded in 1990, is well known for inventing RDRAM and for its intellectual property-based litigation following the introduction of DDR-SDRAM memory.

AMPH vs RMBS — Head-to-Head

Bigger by revenue
AMPH
AMPH
1.0× larger
AMPH
$183.1M
$180.2M
RMBS
Growing faster (revenue YoY)
RMBS
RMBS
+9.9% gap
RMBS
8.1%
-1.8%
AMPH
Higher net margin
RMBS
RMBS
19.9% more per $
RMBS
33.2%
13.3%
AMPH
Faster 2-yr revenue CAGR
RMBS
RMBS
Annualised
RMBS
16.8%
3.2%
AMPH

Income Statement — Q4 FY2025 vs Q1 FY2026

Metric
AMPH
AMPH
RMBS
RMBS
Revenue
$183.1M
$180.2M
Net Profit
$24.4M
$59.9M
Gross Margin
46.8%
79.7%
Operating Margin
19.4%
34.3%
Net Margin
13.3%
33.2%
Revenue YoY
-1.8%
8.1%
Net Profit YoY
-35.7%
-7.3%
EPS (diluted)
$0.51
$0.55

Green = leading value per metric. Periods may differ when fiscal calendars don't align.

8-Quarter Revenue & Profit Trend

Side-by-side quarterly history. Quarters aligned by calendar period so offset fiscal years line up.

Revenue
AMPH
AMPH
RMBS
RMBS
Q1 26
$180.2M
Q4 25
$183.1M
$190.2M
Q3 25
$191.8M
$178.5M
Q2 25
$174.4M
$172.2M
Q1 25
$170.5M
$166.7M
Q4 24
$186.5M
$161.1M
Q3 24
$191.2M
$145.5M
Q2 24
$182.4M
$132.1M
Net Profit
AMPH
AMPH
RMBS
RMBS
Q1 26
$59.9M
Q4 25
$24.4M
$63.8M
Q3 25
$17.4M
$48.4M
Q2 25
$31.0M
$57.9M
Q1 25
$25.3M
$60.3M
Q4 24
$38.0M
$62.2M
Q3 24
$40.4M
$48.7M
Q2 24
$37.9M
$36.1M
Gross Margin
AMPH
AMPH
RMBS
RMBS
Q1 26
79.7%
Q4 25
46.8%
78.9%
Q3 25
51.4%
79.5%
Q2 25
49.6%
79.8%
Q1 25
50.0%
80.3%
Q4 24
46.5%
80.4%
Q3 24
53.3%
80.7%
Q2 24
52.2%
79.7%
Operating Margin
AMPH
AMPH
RMBS
RMBS
Q1 26
34.3%
Q4 25
19.4%
37.2%
Q3 25
13.2%
35.4%
Q2 25
24.2%
36.6%
Q1 25
21.9%
37.9%
Q4 24
24.2%
35.9%
Q3 24
29.8%
37.6%
Q2 24
30.3%
30.5%
Net Margin
AMPH
AMPH
RMBS
RMBS
Q1 26
33.2%
Q4 25
13.3%
33.6%
Q3 25
9.0%
27.1%
Q2 25
17.8%
33.6%
Q1 25
14.8%
36.2%
Q4 24
20.4%
38.6%
Q3 24
21.1%
33.4%
Q2 24
20.8%
27.3%
EPS (diluted)
AMPH
AMPH
RMBS
RMBS
Q1 26
$0.55
Q4 25
$0.51
$0.58
Q3 25
$0.37
$0.44
Q2 25
$0.64
$0.53
Q1 25
$0.51
$0.56
Q4 24
$0.74
$0.57
Q3 24
$0.78
$0.45
Q2 24
$0.73
$0.33

Balance Sheet & Financial Strength

Snapshot of each company's liquidity, leverage and book value from the latest quarter.

Metric
AMPH
AMPH
RMBS
RMBS
Cash + ST InvestmentsLiquidity on hand
$282.8M
$134.3M
Total DebtLower is stronger
$608.7M
Stockholders' EquityBook value
$788.8M
Total Assets
$1.6B
$1.5B
Debt / EquityLower = less leverage
0.77×

8-quarter trend — quarters aligned by calendar period.

Cash + ST Investments
AMPH
AMPH
RMBS
RMBS
Q1 26
$134.3M
Q4 25
$282.8M
$182.8M
Q3 25
$276.2M
$79.2M
Q2 25
$231.8M
$87.8M
Q1 25
$236.9M
$132.2M
Q4 24
$221.6M
$99.8M
Q3 24
$250.5M
$114.0M
Q2 24
$217.8M
$124.6M
Total Debt
AMPH
AMPH
RMBS
RMBS
Q1 26
Q4 25
$608.7M
Q3 25
$608.6M
Q2 25
$607.7M
Q1 25
$603.9M
Q4 24
$601.6M
Q3 24
$596.4M
Q2 24
$586.9M
Stockholders' Equity
AMPH
AMPH
RMBS
RMBS
Q1 26
Q4 25
$788.8M
$1.4B
Q3 25
$776.7M
$1.3B
Q2 25
$757.5M
$1.2B
Q1 25
$751.3M
$1.2B
Q4 24
$732.3M
$1.1B
Q3 24
$727.7M
$1.0B
Q2 24
$713.3M
$1.0B
Total Assets
AMPH
AMPH
RMBS
RMBS
Q1 26
$1.5B
Q4 25
$1.6B
$1.5B
Q3 25
$1.7B
$1.4B
Q2 25
$1.6B
$1.5B
Q1 25
$1.6B
$1.4B
Q4 24
$1.6B
$1.3B
Q3 24
$1.5B
$1.3B
Q2 24
$1.5B
$1.3B
Debt / Equity
AMPH
AMPH
RMBS
RMBS
Q1 26
Q4 25
0.77×
Q3 25
0.78×
Q2 25
0.80×
Q1 25
0.80×
Q4 24
0.82×
Q3 24
0.82×
Q2 24
0.82×

Cash Flow & Capital Efficiency

How much cash each business actually produces after reinvestment. Cash flow is harder to manipulate than net income.

Metric
AMPH
AMPH
RMBS
RMBS
Operating Cash FlowLast quarter
$32.9M
Free Cash FlowOCF − Capex
$24.6M
FCF MarginFCF / Revenue
13.4%
Capex IntensityCapex / Revenue
4.5%
Cash ConversionOCF / Net Profit
1.35×
TTM Free Cash FlowTrailing 4 quarters
$121.2M

8-quarter trend — quarters aligned by calendar period.

Operating Cash Flow
AMPH
AMPH
RMBS
RMBS
Q1 26
Q4 25
$32.9M
$99.8M
Q3 25
$52.6M
$88.4M
Q2 25
$35.6M
$94.4M
Q1 25
$35.1M
$77.4M
Q4 24
$29.0M
$59.0M
Q3 24
$60.0M
$62.1M
Q2 24
$69.1M
$70.4M
Free Cash Flow
AMPH
AMPH
RMBS
RMBS
Q1 26
Q4 25
$24.6M
$93.3M
Q3 25
$47.2M
$82.5M
Q2 25
$25.0M
$87.9M
Q1 25
$24.4M
$69.5M
Q4 24
$16.6M
$52.5M
Q3 24
$46.2M
$52.2M
Q2 24
$63.1M
$59.1M
FCF Margin
AMPH
AMPH
RMBS
RMBS
Q1 26
Q4 25
13.4%
49.0%
Q3 25
24.6%
46.2%
Q2 25
14.3%
51.0%
Q1 25
14.3%
41.7%
Q4 24
8.9%
32.6%
Q3 24
24.1%
35.9%
Q2 24
34.6%
44.7%
Capex Intensity
AMPH
AMPH
RMBS
RMBS
Q1 26
Q4 25
4.5%
3.4%
Q3 25
2.8%
3.3%
Q2 25
6.1%
3.8%
Q1 25
6.3%
4.7%
Q4 24
6.7%
4.0%
Q3 24
7.2%
6.8%
Q2 24
3.3%
8.6%
Cash Conversion
AMPH
AMPH
RMBS
RMBS
Q1 26
Q4 25
1.35×
1.56×
Q3 25
3.03×
1.83×
Q2 25
1.15×
1.63×
Q1 25
1.39×
1.28×
Q4 24
0.76×
0.95×
Q3 24
1.48×
1.28×
Q2 24
1.82×
1.95×

Financial Flow Comparison

Revenue → gross profit → operating profit → net profit for each company.

Revenue Breakdown by Segment

AMPH
AMPH

Other Products$62.4M34%
Baqsimi$46.7M26%
Primatenemist$27.9M15%
Epinephrine$17.1M9%
Lidocaine$14.9M8%
Glucagon$14.1M8%

RMBS
RMBS

Product revenue$88.0M49%
Royalties$69.6M39%
Contract and other revenue$22.6M13%

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