Rubico (RUBI)

Rubico on one page: short interest, daily short volume, fails to deliver, large holders and insider trades. Listed on Nasdaq, classified by the SEC as water transportation.

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264K

Short interest

settlement 2026-10-15

1.0

Days to cover

unchanged vs prior

68.0%

Short share of volume

2026-11-03

239

Fails to deliver

settlement 2026-10-13

Insider flow, 90 days

0 buys, 0 sells

As of 2026-11-03.

Short interest

FINRA, twice a month. The newest 48 settlements in the table, 48 in the chart. JSON

As of 15 October 2026, short interest in RUBI is 264,415 shares, up 223,934 shares over the last month. Over the last 48 readings it ranged from 5,055 shares (15 July 2026) to 10,809,290 shares (30 June 2020). The latest reading sits at the bottom of that range. At the reported average volume of 2.9M shares a day that is 1.0 days to cover.

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Settlement	Shares short	Change	Avg daily volume	Days to cover
2026-10-15	264,415	+273.5%	2,870,866	1.00
2026-09-30	70,792	+74.9%	689,259	1.00
2026-09-15	40,481	+4.0%	69,967	1.00
2026-08-31	38,941	-2.7%	77,857	1.00
2026-08-14	40,014	-21.4%	684,910	1.00
2026-07-31	50,885	+906.6%	2,685,704	1.00
2026-07-15	5,055	-75.1%	124,683	1.00
2026-06-30	20,329	-97.8%	414,183	1.00
2026-06-15	914,104	+1969.2%	46,511,552	1.00
2026-05-29	44,177	-73.0%	6,478,220	1.00
2026-05-15	163,804	+171.3%	77,920	2.10
2026-04-30	60,375	+1.3%	86,791	1.00
2026-04-15	59,604	-76.8%	131,503	1.00
2026-03-31	257,505	-48.2%	647,067	1.00
2026-03-13	497,421	+336.9%	8,716,874	1.00
2026-02-27	113,853	+84.5%	10,555,218	1.00
2026-02-13	61,704	-49.0%	79,503	1.00
2026-01-30	120,875	-45.7%	120,351	1.00
2026-01-15	222,699	+10.5%	1,350,766	1.00
2025-12-31	201,489	-29.3%	582,115	1.00
2025-12-15	285,164	-95.0%	1,228,034	1.00
2025-11-28	5,682,254	+8.9%	97,891,541	1.00
2025-11-14	5,216,827	+2002.6%	82,730,982	1.00
2025-10-31	248,113	+58.3%	276,696	1.00
2025-10-15	156,763	+10.3%	49,404	3.17
2025-09-30	142,093	+490.3%	90,752	1.57
2025-09-15	24,070	+79.8%	35,030	1.00
2025-08-29	13,388	-83.2%	77,937	1.00
2025-08-15	79,826	+100.0%	860,182	1.00
2020-06-30	10,809,290	+16.1%	2,111,752	5.12
2020-06-15	9,308,134	+16.7%	3,047,088	3.05
2020-05-29	7,973,054	+11.5%	2,935,669	2.72
2020-05-15	7,152,409	+22.6%	2,826,489	2.53
2020-04-30	5,271,247	+27.9%	1,905,696	2.77
2020-04-15	4,120,916	+39.0%	2,623,369	1.57
2020-03-31	2,965,610	-34.2%	1,919,127	1.55
2020-03-13	4,507,124	+26.1%	1,837,535	2.45
2020-02-28	3,575,028	-9.1%	2,148,825	1.66
2020-02-14	3,931,959	+7.7%	922,256	4.26
2020-01-31	3,650,019	+5.8%	1,351,253	2.70
2020-01-15	3,450,035	+25.2%	2,006,107	1.72
2019-12-31	2,755,116	+1.8%	1,127,362	2.44
2019-12-13	2,706,366	+20.5%	626,666	4.32
2019-11-29	2,246,636	+3.0%	909,023	2.47
2019-11-15	2,181,344	+15.8%	716,729	3.04
2019-10-31	1,884,197	+18.1%	478,941	3.93
2019-10-15	1,595,763	-12.4%	551,191	2.90
2019-09-30	1,821,425	+0.0%	738,708	2.47

Daily short volume

FINRA Reg SHO, the last 30 sessions. JSON

As of 3 November 2026, the short share of RUBI volume is 68.0%, up 15.1 points over the last five sessions. Over the last 30 readings it ranged from 13.2% (30 September 2026) to 68.0% (3 November 2026). The latest reading sits at the top of that range. The latest reading is 20.9 points above the 30-session average of 47.1%, on 53K shares reported.

Date	Short volume	Total volume	Short share	Exempt
2026-11-03	36K	53K	68.0%	9,280
2026-11-02	18K	31K	57.5%	3,210
2026-10-30	43K	76K	56.2%	9,868
2026-10-29	240K	723K	33.2%	36,550
2026-10-28	773K	1.6M	47.5%	127,059
2026-10-27	312K	588K	53.0%	56,693
2026-10-26	202K	420K	48.1%	18,844
2026-10-23	830K	1.4M	59.8%	162,225
2026-10-22	518K	892K	58.1%	130,292
2026-10-21	1.0M	1.9M	54.1%	174,750
2026-10-20	1.9M	3.7M	50.5%	152,134
2026-10-19	20.7M	35.1M	59.0%	4,050,251
2026-10-16	7.7M	13.4M	57.7%	90,570
2026-10-15	65K	120K	54.3%	110
2026-10-14	41K	87K	47.1%	118
2026-10-13	152K	302K	50.3%	26,299
2026-10-12	64K	255K	25.1%	740
2026-10-09	75K	168K	44.9%	2,693
2026-10-08	28K	93K	30.1%	1,831
2026-10-07	52K	143K	36.6%	4,923
2026-10-06	1.0M	1.9M	55.1%	74,432
2026-10-05	13K	22K	58.2%	0
2026-10-02	15K	27K	57.2%	0
2026-10-01	8K	20K	40.3%	0
2026-09-30	4K	29K	13.2%	0
2026-09-29	7K	24K	29.8%	0
2026-09-28	10K	72K	14.0%	0
2026-09-25	99K	153K	64.4%	5
2026-09-24	27K	59K	46.7%	1,386
2026-09-23	21K	47K	44.0%	1,636

Fails to deliver

SEC, the last 30 settlement dates with a fail. JSON

As of 13 October 2026, the fails-to-deliver balance in RUBI is 239 shares, down 14 shares over the last settlement date. Over the last 30 readings it ranged from 14 shares (12 August 2026) to 132,116 shares (4 August 2026). The latest reading sits at the bottom of that range.

Settlement	Shares failed	Price	Value
2026-10-13	239	$0.42	$100
2026-10-09	253	$0.59	$149
2026-10-08	284	$0.62	$176
2026-10-07	9,668	$0.65	$6K
2026-10-05	95	$1.08	$103
2026-09-29	79	$1.13	$89
2026-09-28	4,953	$1.13	$6K
2026-09-25	1,916	$1.20	$2K
2026-09-23	3,216	$1.14	$4K
2026-09-22	10,225	$1.25	$13K
2026-09-21	5,134	$1.14	$6K
2026-09-18	17,434	$1.43	$25K
2026-09-15	24	$1.54	$37
2026-09-09	6,775	$1.77	$12K
2026-09-08	2,543	$1.82	$5K
2026-09-04	3,400	$1.83	$6K
2026-08-19	1,899	$1.89	$4K
2026-08-12	14	$2.27	$32
2026-08-11	285	$2.23	$636
2026-08-10	151	$2.25	$340
2026-08-06	642	$2.39	$2K
2026-08-05	2,888	$2.32	$7K
2026-08-04	132,116	$2.34	$309K
2026-08-03	4,985	$2.23	$11K
2026-07-31	8,057	$2.27	$18K
2026-07-30	521	$2.17	$1K
2026-07-29	13,548	$2.16	$29K
2026-07-28	557	$2.11	$1K
2026-07-27	17,799	$2.22	$40K
2026-07-24	915	$2.36	$2K

Insider trades

SEC Form 4, newest first. JSON

No open-market insider trades were reported for RUBI in the last 90 days. The most recent filings are listed below. Latest filing: HRT FINANCIAL LP (TenPercentOwner) on 2026-06-12.

Date	Insider	Title	Type	Shares	Price	Value	Owned after
2026-06-12	HRT FINANCIAL LP	TenPercentOwner	Sell	551K	$0.95	$523K	0
2026-06-11	HRT FINANCIAL LP	TenPercentOwner	Buy	485K	$0.81	$393K	385K

Form 4 filings are due within two business days of the trade. Insiders sell for many reasons that say nothing about the company; open-market buys are rarer.

Large holders (13D and 13G)

One row per reporting person with its latest filing, newest first. JSON

No holder on file reports 5% or more of RUBI in its latest filing.

Filed	Form	Holder	Shares	Of class	Event
2026-06-12	13G/Ano. 1	Trillium Trading, LLCother entity	0	0.0%	2026-06-11
2026-02-17	13G/Ano. 1	L1 Capital Global Opportunities Master Fund, Ltd.non-US institution	0	0.0%	2025-12-31
2026-02-13	13G/Ano. 1	Arena Special Opportunities (Offshore) Master, LPpartnership	0	0.0%	2025-12-31
2026-02-13	13G/Ano. 1	Arena Special Opportunities Fund (Offshore) II GP, LPpartnership	0	0.0%	2025-12-31
2026-02-13	13G/Ano. 1	Arena Special Opportunities Fund (Offshore) GP, LLCother entity	0	0.0%	2025-12-31
2026-02-13	13G/Ano. 1	Arena Special Opportunities Parallel Investor Vehicle III GP, LLCother entity	0	0.0%	2025-12-31
2026-02-13	13G/Ano. 1	Arena Special Opportunities Partners III, LPpartnership	0	0.0%	2025-12-31
2026-02-13	13G/Ano. 1	Arena Special Opportunities Partners III GP, LLCother entity	0	0.0%	2025-12-31
2026-02-13	13G/Ano. 1	Arena Special Opportunities Parallel Investor Vehicle III US, LPpartnership	0	0.0%	2025-12-31
2026-02-13	13G/Ano. 1	Arena Investors, LPinvestment adviser	0	0.0%	2025-12-31
2026-02-13	13G/Ano. 1	Arena Investors GP, LLCother entity	0	0.0%	2025-12-31
2025-11-17	13D/Ano. 4	Family Trading Inc.corporation	1.5M	3.3%	2025-11-12
2025-11-17	13D/Ano. 4	3 Sororibus Trustother entity	1.5M	3.3%	2025-11-12
2025-11-17	13D/Ano. 4	Evangelos J. Pistiolisother entity	221K	0.5%	2025-11-12

What this page is

Rubico in the regulatory record

Regulators publish company data in separate files that never sit next to each other: FINRA's twice-monthly short interest, its daily short sale volume, the SEC's fails-to-deliver counts, and each insider's Form 4. A company page puts those series for one ticker on one URL, with planned sales, large holders, 13F holders and financials beside them, so the short position, the daily flow, the settlement fails and what insiders are doing can be read together.

Each section has its own history table, a one-line summary of the latest figures and its own JSON and CSV links, and says when its source last updated.

This page follows Rubico (RUBI), SEC CIK 1943421, listed on Nasdaq, classified by the SEC as water transportation. The cross-market tables live on the short interest and insider transactions hubs.

Source and updates

Short interest: FINRA consolidated short interestSource: FINRA.Twice a month, about eight business days after settlement. Latest 2026-10-15.JSON and CSV
Daily short volume: FINRA Reg SHO daily filesSource: FINRA.Every trading day, the morning after FINRA posts it. Latest 2026-11-03.JSON and CSV
Fails to deliver: SEC fails-to-deliver dataSource: SEC.Twice a month, a few weeks after the half month ends. Latest 2026-10-13.JSON and CSV
Large holders: SEC EDGAR Schedule 13D and 13GSource: SEC.New filings appear shortly after the SEC posts them. A 13D is due within five business days of crossing 5%; a 13G follows the passive schedule. Latest 2026-06-12.JSON and CSV
Insider trades: SEC EDGAR Form 4Source: SEC.New filings appear shortly after the SEC posts them; they're due two business days after the trade. Latest 2026-06-12.JSON and CSV
Company record: EDGAR filing index for CIK 1943421Ticker, name and exchange from the SEC's company list, refreshed weekly.
Rate limits: 10 requests a minute without a key, 30 with a free key from a free account.

How to read it

Read the position against the flow: rising short interest with a high daily short share is new shorting; rising short interest with a normal short share is old shorts holding on.
Insider buys next to a large short position are rare and stand out; insider sells next to one are common and mean little.
Fails to deliver matter relative to the float, not in absolute shares; a million failed shares in a mega cap is noise.

Analysis of what the data shows, not advice. XOOMAR does not recommend buying, selling or holding anything.

Other companies the SEC classifies as water transportation

Other company pages

Datasets

Frequently Asked Questions

How much of RUBI is sold short?

264,415 shares were held short at the 2026-10-15 settlement, 1.0 days of average volume. FINRA publishes the next count about eight business days after the 15th and the last business day of the month.

What is RUBI's daily short volume?

On 2026-11-03, 36,252 of the 53,281 RUBI shares reported to FINRA were sold short, 68.0% of the day's reported volume. Short volume is a flow for one day, not a position.

Does RUBI have fails to deliver?

The SEC's latest file shows 239 RUBI shares failed to deliver at settlement 2026-10-13. Fails are reported per settlement date and published twice a month with a lag.

Are RUBI insiders buying or selling?

No open-market insider trades were reported for RUBI in the last 90 days. The most recent filings are listed below. Latest filing: HRT FINANCIAL LP (TenPercentOwner) on 2026-06-12.

Who owns 5% or more of RUBI?

No holder on file reports 5% or more of RUBI in its latest filing.

Data on this page is provided for informational purposes only and is not financial advice. See our editorial policy.