Q1 2024 · 13F-HR
OBERWEIS ASSET MANAGEMENT INC/holdings as filed
Filed 2024-05-15 · accession 0001213900-24-043291
$1.38B
Reported value
196
Positions
2024-03-31
Period end
Holdings as filed
| CUSIP | Ticker | Issuer | Value | % port. | Shares | Class | Voting |
|---|---|---|---|---|---|---|---|
| F21107101 | CSTM | Constellium NV Cl A | $39.9M | 2.88% | 1,803,271 | Common | SOLE |
| G48833118 | WFRD | Weatherford International PLC | $25.6M | 1.85% | 222,100 | Common | SOLE |
| 054540208 | ACLS | Axcelis Technologies | $23.3M | 1.69% | 209,339 | Common | SOLE |
| 683344105 | ONTO | Onto Innovation, Inc. | $19.4M | 1.40% | 106,930 | Common | SOLE |
| 02081G201 | ATEC | Alphatec Hldgs Inc. | $19.1M | 1.38% | 1,385,880 | Common | SOLE |
| 92537N108 | VRT | Vertiv Holdings Co. | $18.8M | 1.36% | 229,650 | Common | SOLE |
| 000899104 | ADMA | ADMA Biologics, Inc. | $18.4M | 1.33% | 2,790,700 | Common | SOLE |
| 03209R103 | AMPH | Amphastar Pharmaceuticals, Inc | $18.3M | 1.33% | 417,865 | Common | SOLE |
| 830879102 | SKYW | Skywest Inc | $18.1M | 1.31% | 262,360 | Common | SOLE |
| 29261A100 | EHC | Encompass Health Corporation | $16.9M | 1.22% | 204,136 | Common | SOLE |
| 82706C108 | SIMO | Silicon Motion Techn ADR | $16.7M | 1.21% | 217,400 | Common | SOLE |
| 688239201 | OSK | Oshkosh Corp. | $16.7M | 1.21% | 133,827 | Common | SOLE |
| 184496107 | CLH | Clean Harbors, Inc. | $16.4M | 1.18% | 81,295 | Common | SOLE |
| 008073108 | AVAV | Aerovironment, Inc. | $15.6M | 1.13% | 101,570 | Common | SOLE |
| M20791105 | CAMT | Camtek, Ltd. | $14.9M | 1.08% | 178,180 | Common | SOLE |
| 92337F107 | VCYT | Veracyte, Inc. | $14.9M | 1.08% | 671,700 | Common | SOLE |
| 90385V107 | UCTT | Ultra Clean Holdings | $14.7M | 1.06% | 319,600 | Common | SOLE |
| 89377M109 | TMDX | TransMedics Group, Inc. | $14.7M | 1.06% | 198,200 | Common | SOLE |
| G8068L108 | SN | SharkNinja, Inc. | $14.7M | 1.06% | 235,200 | Common | SOLE |
| 44925C103 | ICFI | ICF International, Inc. | $14.6M | 1.06% | 96,900 | Common | SOLE |
| 29605J106 | ESAB | ESAB Corporation | $14.3M | 1.03% | 129,200 | Common | SOLE |
| 70202L102 | PSN | Parsons Corp. | $14.3M | 1.03% | 172,140 | Common | SOLE |
| 227046109 | CROX | Crocs, Inc. | $13.7M | 0.99% | 95,400 | Common | SOLE |
| 65290E101 | NXT | Nextracker, Inc. | $13.3M | 0.96% | 235,700 | Common | SOLE |
| 91347P105 | OLED | Universal Display Corp. | $13.0M | 0.94% | 77,442 | Common | SOLE |
| 98956A105 | ZETA | Zeta Global Holdings Corp. | $12.9M | 0.93% | 1,181,980 | Common | SOLE |
| 00108J109 | ACMR | ACM Research, Inc. Class A | $12.9M | 0.93% | 441,130 | Common | SOLE |
| 34354P105 | FLS | Flowserve Corporation | $12.5M | 0.91% | 274,378 | Common | SOLE |
| 405024100 | HAE | Haemonetics Corp. | $12.3M | 0.89% | 143,695 | Common | SOLE |
| 00404A109 | ACHC | Acadia Healthcare Co., Inc. | $12.0M | 0.87% | 151,650 | Common | SOLE |
| 00760J108 | AEHR | Aehr Test Systems | $12.0M | 0.87% | 967,852 | Common | SOLE |
| 589889104 | MMSI | Merit Medical System Inc | $11.9M | 0.86% | 156,490 | Common | SOLE |
| 03823U102 | AAOI | Applied Optoelectronics Inc. | $11.8M | 0.85% | 849,615 | Common | SOLE |
| 156504300 | CCS | Century Communities, Inc. | $11.7M | 0.85% | 121,200 | Common | SOLE |
| 33768G107 | FCFS | FirstCash Holdings, Inc | $11.7M | 0.85% | 91,700 | Common | SOLE |
| 465741106 | ITRI | Itron Inc | $11.6M | 0.84% | 125,600 | Common | SOLE |
| 64049M209 | NEO | NeoGenomics, Inc. | $11.6M | 0.84% | 737,200 | Common | SOLE |
| 095306106 | BLBD | Blue Bird Corporation | $11.5M | 0.83% | 299,100 | Common | SOLE |
| 004498101 | ACIW | ACI Worldwide Inc. | $11.4M | 0.83% | 344,562 | Common | SOLE |
| G5509L101 | LIVN | LivaNova Plc | $11.3M | 0.82% | 202,500 | Common | SOLE |
| 45826H109 | ITGR | Integer Holdings Corporation | $11.3M | 0.82% | 96,700 | Common | SOLE |
| 05465P101 | AXNX* | Axonics, Inc. | $11.3M | 0.82% | 163,570 | Common | SOLE |
| 826919102 | SLAB | Silicon Laboratories, Inc. | $11.2M | 0.81% | 78,000 | Common | SOLE |
| 30050B101 | EVH | Evolent Health, Inc. | $11.1M | 0.80% | 338,940 | Common | SOLE |
| 05478C105 | AZEK | Azek Co., Inc. | $11.1M | 0.80% | 220,900 | Common | SOLE |
| 313855108 | FSS | Federal Signal Corp. | $10.8M | 0.78% | 127,830 | Common | SOLE |
| 45674M101 | INFA1EUR | Informatica Corp. | $10.8M | 0.78% | 309,000 | Common | SOLE |
| 346375108 | FORM | Formfactor Inc. | $10.8M | 0.78% | 236,700 | Common | SOLE |
| 125141101 | CECO | CECO Environmental Corp. | $10.7M | 0.77% | 463,400 | Common | SOLE |
| 859241101 | STRL | Sterling Construction Co., Inc | $10.7M | 0.77% | 96,600 | Common | SOLE |
| 18467V109 | YOU | Clear Secure, Inc. | $10.6M | 0.77% | 500,500 | Common | SOLE |
| Y41053102 | INSW | International Seaways, Inc. | $10.6M | 0.76% | 198,700 | Common | SOLE |
| 980745103 | WWD | Woodward, Inc. | $10.5M | 0.76% | 68,400 | Common | SOLE |
| 47103N106 | JBI | Janus International Group, Inc | $10.5M | 0.76% | 695,400 | Common | SOLE |
| 53815P108 | RAMP | Liveramp Hldgs, Inc. | $10.2M | 0.74% | 295,780 | Common | SOLE |
| 922417100 | VECO | Veeco Instruments, Inc. | $9.5M | 0.68% | 269,100 | Common | SOLE |
| 74164F103 | PRIM | Primoris Services Corp. | $8.9M | 0.65% | 209,900 | Common | SOLE |
| 243537107 | DECK | Deckers Outdoor Corp. | $8.9M | 0.64% | 9,420 | Common | SOLE |
| 35905A109 | FTDR | Frontdoor, Inc. | $8.6M | 0.62% | 263,300 | Common | SOLE |
| 030111207 | AMSC | American Superconductor | $8.6M | 0.62% | 634,400 | Common | SOLE |
| 26856L103 | ELF | e.l.f. Beauty, Inc. | $8.6M | 0.62% | 43,720 | Common | SOLE |
| 553498106 | MSA | MSA Safety Inc | $8.6M | 0.62% | 44,200 | Common | SOLE |
| 39874R101 | GO | Grocery Outlet Hldg Corp. | $8.5M | 0.62% | 296,000 | Common | SOLE |
| 78473E103 | SPXC | SPX Technologies, Inc. | $8.5M | 0.61% | 69,000 | Common | SOLE |
| 127055101 | CBT | Cabot Corp. | $8.5M | 0.61% | 92,100 | Common | SOLE |
| 04621X108 | AIZ | Assurant, Inc. | $8.5M | 0.61% | 45,000 | Common | SOLE |
| 747316107 | KWR | Quaker Chemical Corporation | $8.3M | 0.60% | 40,500 | Common | SOLE |
| 671044105 | OSIS | Osi Systems, Inc. | $7.9M | 0.57% | 55,300 | Common | SOLE |
| 45780R101 | IBP | Installed Building Products, I | $7.9M | 0.57% | 30,400 | Common | SOLE |
| 302301106 | EZPW | EZCorp, Inc. | $7.8M | 0.56% | 685,500 | Common | SOLE |
| 05366Y201 | AVNW | Aviat Networks, Inc. | $7.6M | 0.55% | 199,307 | Common | SOLE |
| 577933104 | MMS | Maximus, Inc. | $7.5M | 0.54% | 89,700 | Common | SOLE |
| 974155103 | WING | Wingstop, Inc. | $7.3M | 0.53% | 20,000 | Common | SOLE |
| 14888U101 | CPRX | Catalyst Pharmaceuticals, Inc. | $7.3M | 0.53% | 458,400 | Common | SOLE |
| 740367404 | PFBC | Preferred Bank | $7.3M | 0.53% | 95,000 | Common | SOLE |
| N70544106 | PL0 | Playa Hotels & Resorts N.V. | $7.3M | 0.53% | 751,500 | Common | SOLE |
| 01741R102 | ATI | ATI, Inc. | $7.3M | 0.53% | 141,900 | Common | SOLE |
| 719405102 | PLAB | Photronics, Inc. | $7.3M | 0.52% | 256,100 | Common | SOLE |
| 94724R108 | WEAV | Weave Communications, Inc. | $7.0M | 0.51% | 609,400 | Common | SOLE |
| 53263P105 | LMB | Limbach Hldgs, Inc. | $6.8M | 0.49% | 164,800 | Common | SOLE |
| G25457105 | CRDO | Credo Technology Group | $6.8M | 0.49% | 321,900 | Common | SOLE |
| 458334109 | IPAR | Inter Parfums | $6.8M | 0.49% | 48,300 | Common | SOLE |
| 78349D107 | RXST | RxSight, Inc. | $6.5M | 0.47% | 126,640 | Common | SOLE |
| 749660106 | RES | RPC, Inc. | $6.5M | 0.47% | 838,476 | Common | SOLE |
| 609027107 | MCRI | Monarch Casino & Resort, Inc. | $6.5M | 0.47% | 86,200 | Common | SOLE |
| 36237H101 | GIII | G-III Apparel Group Ltd. | $6.4M | 0.46% | 220,900 | Common | SOLE |
| 501147102 | KRYS | Krystal Biotech, Inc. | $6.4M | 0.46% | 35,700 | Common | SOLE |
| 199908104 | FIX | Comfort Systems USA Inc. | $6.3M | 0.45% | 19,800 | Common | SOLE |
| 71639T106 | PETQEUR | PetlQ Inc | $6.2M | 0.45% | 340,700 | Common | SOLE |
| 607828100 | MOD | Modine Mfg Co Com | $6.1M | 0.44% | 64,500 | Common | SOLE |
| 002896207 | ANF | Abercrombie & Fitch Co. | $6.0M | 0.44% | 48,100 | Common | SOLE |
| 89531P105 | TREX | Trex Company, Inc. | $6.0M | 0.43% | 60,100 | Common | SOLE |
| 228903100 | AORT | Artivion, Inc | $6.0M | 0.43% | 282,400 | Common | SOLE |
| 01749D105 | ALGM | Allegro MicroSystems, Inc. | $6.0M | 0.43% | 221,280 | Common | SOLE |
| 74167P108 | BCBUSD | Primo Water Corp. | $5.9M | 0.43% | 323,500 | Common | SOLE |
| 38526M106 | LOPE | Grand Canyon Education, Inc. | $5.9M | 0.43% | 43,200 | Common | SOLE |
| 91688F104 | UPWK | Upwork, Inc. | $5.8M | 0.42% | 469,200 | Common | SOLE |
| 516806205 | 8LP1 | Vital Energy, Inc. | $5.7M | 0.42% | 109,400 | Common | SOLE |
| 268158201 | DVAX | Dynavax Technologies Corp. | $5.7M | 0.42% | 462,700 | Common | SOLE |
| 30052C107 | EOLS | Evolus, Inc. | $5.6M | 0.40% | 397,300 | Common | SOLE |
| P73684113 | OSW | OneSpaWorld Holdings Limited | $5.6M | 0.40% | 420,400 | Common | SOLE |
| 576485205 | MTDR | Matador Resources Company | $5.5M | 0.40% | 82,400 | Common | SOLE |
| 525558201 | LMAT | LeMaitre Vascular, Inc. | $5.3M | 0.38% | 80,001 | Common | SOLE |
| 918284100 | VSEC | VSE Corp. | $5.3M | 0.38% | 66,300 | Common | SOLE |
| 099406100 | BOOT | Boot Barn Hldgs, Inc. | $5.2M | 0.37% | 54,400 | Common | SOLE |
| 829073105 | SSD | Simpson Manufacturing | $5.1M | 0.37% | 24,800 | Common | SOLE |
| 825704109 | SIBN | SI-BONE, Inc. | $5.1M | 0.37% | 310,400 | Common | SOLE |
| 782011100 | RSI | Rush Street Interactive, Inc. | $5.1M | 0.37% | 776,700 | Common | SOLE |
| 55305B101 | MHO | M/I Homes, Inc. | $4.9M | 0.36% | 36,200 | Common | SOLE |
| 866683105 | SNCY | Sun Country Airlines Holdings, | $4.9M | 0.36% | 325,600 | Common | SOLE |
| 18538R103 | CLW | Clearwater Paper Corp | $4.9M | 0.35% | 112,200 | Common | SOLE |
| 53115L104 | LBRT | Liberty Energy, Inc. | $4.9M | 0.35% | 236,300 | Common | SOLE |
| 559663109 | MGY | Magnolia Oil & Gas Corp. | $4.8M | 0.35% | 184,600 | Common | SOLE |
| 447462102 | HURN | Huron Consulting Group, Inc. | $4.8M | 0.34% | 49,200 | Common | SOLE |
| 753422104 | RPD | Rapid7, Inc. | $4.6M | 0.34% | 94,500 | Common | SOLE |
| 404030108 | HEESEUR | H&E Equipment Services, Inc. | $4.5M | 0.32% | 69,500 | Common | SOLE |
| 42330P107 | HLX | Helix Energy Solutions Group, | $4.4M | 0.32% | 407,500 | Common | SOLE |
| 144285103 | CRS | Carpenter Technology Corp. | $4.4M | 0.32% | 61,800 | Common | SOLE |
| M2197Q107 | CLBT | Cellebrite DI Ltd. | $4.4M | 0.32% | 397,900 | Common | SOLE |
| 687793109 | OSCR | Oscar Health, Inc. | $4.4M | 0.32% | 295,000 | Common | SOLE |
| 80874P109 | LNWO | Light & Wonder Inc. | $4.3M | 0.31% | 42,600 | Common | SOLE |
| 830940102 | SKWD | Skyward Specialty Ins Group | $4.3M | 0.31% | 115,700 | Common | SOLE |
| 320817109 | FRME | First Merchants Corporation | $4.3M | 0.31% | 123,400 | Common | SOLE |
| 000360206 | AAON | AAON, Inc. | $4.3M | 0.31% | 48,400 | Common | SOLE |
| 374689107 | ROCK | Gibraltar Inds | $4.3M | 0.31% | 52,800 | Common | SOLE |
| 09227Q100 | BLKB | Blackbaud | $4.2M | 0.31% | 57,300 | Common | SOLE |
| 302081104 | EXLS | Exlservice Holdings | $4.2M | 0.31% | 133,200 | Common | SOLE |
| 62955J103 | NOV | NOV, Inc. | $4.2M | 0.31% | 216,900 | Common | SOLE |
| 37253A103 | THRM | Gentherm, Inc. | $4.2M | 0.31% | 73,500 | Common | SOLE |
| 42226A107 | HQY | HealthEquity Inc. | $4.2M | 0.30% | 51,300 | Common | SOLE |
| 85208M102 | SFM | Sprouts Farmers Markets LLC | $4.2M | 0.30% | 64,700 | Common | SOLE |
| 26603R106 | DUOL | Duolingo, Inc. | $4.2M | 0.30% | 18,900 | Common | SOLE |
| 267475101 | DY | Dycom Industries, Inc. | $4.2M | 0.30% | 29,000 | Common | SOLE |
| 86333M108 | LRN | Stride, Inc. | $4.2M | 0.30% | 66,000 | Common | SOLE |
| G3323L100 | FN | Fabrinet | $4.1M | 0.30% | 21,900 | Common | SOLE |
| 47580P103 | JELD | JELD-WEN Holding, Inc. | $4.1M | 0.30% | 192,600 | Common | SOLE |
| 127387108 | CDNS | Cadence Design System, Inc. | $4.1M | 0.29% | 13,100 | Common | SOLE |
| 92846Q107 | COCO | The Vita Coco Co., Inc. | $4.0M | 0.29% | 165,400 | Common | SOLE |
| 74022D407 | PDS | Precision Drilling Corp. | $4.0M | 0.29% | 59,700 | Common | SOLE |
| 292218104 | EIG | Employers Holdings, Inc. | $3.9M | 0.28% | 86,100 | Common | SOLE |
| 63942X106 | NVTS | Navitas Semiconductor Corp. | $3.9M | 0.28% | 807,400 | Common | SOLE |
| 45245E109 | IMAX | Imax Corp. | $3.8M | 0.28% | 236,200 | Common | SOLE |
| 404251100 | HNI | HNI Corp. | $3.8M | 0.27% | 83,400 | Common | SOLE |
| 05637B105 | BLZE | Backblaze, Inc. | $3.7M | 0.26% | 357,800 | Common | SOLE |
| 56400P706 | MNKD | Mannkind Corp. | $3.6M | 0.26% | 798,800 | Common | SOLE |
| 743713109 | PRLB | Proto Labs Inc. | $3.5M | 0.25% | 97,500 | Common | SOLE |
| 04206A101 | ARLO | Arlo Technologies, Inc. | $3.5M | 0.25% | 273,400 | Common | SOLE |
| 587376104 | MBWM | Mercantile Bank Corp. | $3.4M | 0.25% | 89,328 | Common | SOLE |
| 336901103 | SRCE | 1st Source Corp. | $3.3M | 0.24% | 63,900 | Common | SOLE |
| 893529107 | TRNS | Transcat, Inc. | $3.2M | 0.23% | 29,100 | Common | SOLE |
| 00182C103 | ANIP | ANI Pharmaceuticals, Inc. | $3.0M | 0.22% | 43,500 | Common | SOLE |
| Y2106R110 | LPG | Dorian LPG Ltd. | $2.9M | 0.21% | 75,500 | Common | SOLE |
| 420261109 | HWKN | Hawkins, Inc. | $2.9M | 0.21% | 37,200 | Common | SOLE |
| 749527107 | 1RG | Rev Group, Inc. | $2.8M | 0.20% | 126,300 | Common | SOLE |
| 04041L106 | ARISUSD | Aris Water Solutions, Inc. | $2.8M | 0.20% | 195,200 | Common | SOLE |
| 292765104 | EPAC | Enerpac Tool Group Corp. | $2.8M | 0.20% | 77,300 | Common | SOLE |
| 383082104 | GRC | The Gorman-Rupp Co. | $2.7M | 0.20% | 68,900 | Common | SOLE |
| 691497309 | OXM | Oxford Inds, Inc. | $2.6M | 0.19% | 23,400 | Common | SOLE |
| 576853105 | MTRX | Matrix Service Co. | $2.6M | 0.19% | 198,500 | Common | SOLE |
| 874039100 | TSM | Taiwan Semiconductor ADR | $2.5M | 0.18% | 18,500 | Common | SOLE |
| 87043Q108 | SG | Sweetgreen, Inc. | $2.5M | 0.18% | 97,851 | Common | SOLE |
| 739128106 | POWL | Powell Industries Inc. | $2.4M | 0.17% | 16,800 | Common | SOLE |
| 74766Q101 | QTRX | Quanterix Corp. | $2.3M | 0.17% | 99,700 | Common | SOLE |
| 05463X106 | AXGN | AxoGen Inc. | $2.3M | 0.17% | 286,400 | Common | SOLE |
| 22207T101 | BASE | Couchbase, Inc. | $2.3M | 0.17% | 87,800 | Common | SOLE |
| 09180C106 | BJRI | BJ's Restaurants, Inc. | $2.3M | 0.17% | 63,600 | Common | SOLE |
| 53635D202 | LQDA | Liquidia Corp. | $2.2M | 0.16% | 150,000 | Common | SOLE |
| 053604104 | AVPT | AvePoint, Inc. | $2.1M | 0.15% | 266,800 | Common | SOLE |
| 78462F103 | SPY | SPDR S&P 500 ETF Trust | $1.9M | 0.14% | 3,576 | Common | NONE |
| 722304102 | PDD | PDD Holdings Inc. ADR | $1.7M | 0.12% | 14,500 | Common | SOLE |
| 594918104 | MSFT | Microsoft Corp. | $1.1M | 0.08% | 2,725 | Common | NONE |
| 88034P109 | TME | Tencent Music Entertainment AD | $895,200 | 0.06% | 80,000 | Common | SOLE |
| G0457F107 | ARCO | Arcos Dorados Holdings, Inc. | $874,032 | 0.06% | 78,600 | Common | SOLE |
| 46625H100 | JPM | JP Morgan Chase & Company Inc. | $762,021 | 0.06% | 3,804 | Common | NONE |
| 50202M102 | LI | Li Auto, Inc. ADR | $696,440 | 0.05% | 23,000 | Common | SOLE |
| 66981J102 | MNSO | MINISO Group Holding Limited A | $615,000 | 0.04% | 30,000 | Common | SOLE |
| V5633W109 | MMYT | MakeMyTrip Ltd. | $611,030 | 0.04% | 8,600 | Common | SOLE |
| 037833100 | AAPL | Apple, Inc. | $579,826 | 0.04% | 3,381 | Common | NONE |
| G9470A102 | VTEX | VTEX | $543,305 | 0.04% | 66,500 | Common | SOLE |
| 89417E109 | TRV | The Travelers Co., Inc. | $468,600 | 0.03% | 2,036 | Common | NONE |
| 48553T106 | BZ | Kanzhun Limited ADR | $438,250 | 0.03% | 25,000 | Common | SOLE |
| 57636Q104 | MA | Mastercard, Inc. | $373,505 | 0.03% | 776 | Common | NONE |
| 478160104 | JNJ | Johnson & Johnson | $342,865 | 0.02% | 2,167 | Common | NONE |
| 52490G102 | LEGN | Legend Biotech Corp. ADR | $336,540 | 0.02% | 6,000 | Common | SOLE |
| 031162100 | AMGN | Amgen, Inc. | $304,262 | 0.02% | 1,070 | Common | NONE |
| 761152107 | RMD | Resmed Inc. | $287,144 | 0.02% | 1,450 | Common | NONE |
| 874080104 | TAL | Tal Education Group ADR | $283,750 | 0.02% | 25,000 | Common | SOLE |
| G27358103 | DESP1EUR | Despegar Com Corp. | $269,100 | 0.02% | 22,500 | Common | SOLE |
| G0896C103 | TBBB | BBB Foods, Inc. | $261,580 | 0.02% | 11,000 | Common | SOLE |
| 15118V207 | CELH | Celsius Hldgs Inc. | $248,760 | 0.02% | 3,000 | Common | NONE |
| G0260P102 | AS | Amer Sports, Inc. | $244,500 | 0.02% | 15,000 | Common | SOLE |
| 580135101 | MCD | McDonald's Corporation | $238,009 | 0.02% | 844 | Common | NONE |
| 58933Y105 | MRK | Merck & Co. | $228,274 | 0.02% | 1,730 | Common | NONE |
| 892331307 | TM | Toyota Motor Corp. ADR | $202,654 | 0.01% | 805 | Common | NONE |
| 98401A106 | — | Xenacare Hldgs, Inc. | $0 | — | 140,000 | Common | NONE |
| 001ESC102 | — | AMR Corp Escrow | $0 | — | 18,000 | Common | SOLE |
Source: SEC EDGAR · raw 13F holdings as filed. The Class column shows the option type when reported (Put/Call) or Common when the issuer's equity is held directly. 13F discloses long positions only.