aking a closer look at industry ownership, only data from TractIQ and MSM’s 2025 Top Operator’s list were used for this section.

In analyzing ownership data among the top 100 operators, we look at four groups:

• Real estate investment trusts,
• Other Top Operators with portfolios of both properties owned and managed,
• Other Top Operators whose portfolios only include properties they own, and
• Other Top Operators whose portfolios only include properties they manage.

The five largest self-storage operators (REITs and U-Haul, a publicly traded company) comprise 19.3 percent of facilities and 35.6 percent of rentable square footage. Their portfolios include properties they own and manage, except for National Storage Affiliates (NSA), whose portfolio does not include any third-party managed facilities as of 2025.

See Charts 2.1 and 2.2.

Other Top Operators, ranked No. 6 to 100 on the list, have portfolios of owned facilities only, managed facilities only, or both owned and managed. Other Top Operators represent 14.3 percent of the market share by number of facilities and 27.1 percent of the market share by rentable square footage.

Other Top Operators whose portfolios only include properties they own comprise 40 companies on the 2025 list of top 100 operators. Thirty-eight operators both own and manage self-storage facilities. Finally, 17 companies on the Top Operators list only provide third-party management; they do not own any facilities.

Adding up the five REITs, 38 top operators with both owned and managed facilities, 40 with owned facilities only, and 17 with exclusively managed facilities brings us to 100 operators on the list.

In 2025, 27 operators were considered “new” to the Top Operators list; they didn’t rank on the 2024 list, but some had been ranked in previous years, and consolidation has (and will continue) to make way for new entrants, such as StoragePRO’s (No. 26) acquisition of Storage Investment Management, Inc. (SIMI) in January. Of those 27, 14 own properties exclusively and do not offer third-party management. Conversely, four of 2025’s new entrants provide third-party management but do not own any facilities.

See Table 2.1.

The largest self-storage operator for the third year in a row is Extra Space Storage, which expanded its portfolio by nearly 30 million net rentable square feet (NRSF) in 12 months (from 2024 to 2025); that’s an addition of three times as much NRSF than the approximately 10 million NRSF added from 2023 to 2024. On top of that astonishing growth, the REIT reported that it was managing roughly 17 million NRSF more than it owned in 2025.

Like 2024, Public Storage, the second-largest operator, grew its portfolio by another approximately 11 million NRSF. Although about half of that amount (approximately 5 million NRSF) was added to the management side of its portfolio, Extra Space Storage still manages five times as much net rentable square feet in the United States than Public Storage.

Once again claiming third place is CubeSmart, which manages almost 2 million more NRSF than it owns. And with approximately 53.2 million NRSF of storage managed, roughly 20 million more than Public Storage, CubeSmart has the second-largest third-party managed portfolio in the self-storage industry.

Rounding out the REITs are U-Haul International (No. 4) and National Storage Affiliates Trust (No. 5). Their ranks remain unchanged from 2024, even though they each added about 1 million NRSF to their portfolios since the 2024 Top Operators Survey was completed.

Of special note: Next year’s REIT data will include SmartStop Self Storage, which became a REIT in the second quarter of 2025.

See Table 2.2.

As for the rest of the 2025 top operators, Storage Asset Management (SAM), ranked No. 6, has the third-largest third-party management portfolio at 37,620,000 net rentable square feet. SmartStop Self Storage took 7^th place—a climb of four places since ranking No. 11 in 2024. SmartStop’s quick growth can be attributed to it becoming a publicly traded company in 2025. Its initial public offering (IPO) was completed in April, listing on the New York Stock Exchange (NYSE). Four months later, SmartStop Self Storage REIT was added to the Morgan Stanley Capital International U.S. Real Estate Investment Trust (MSCI US REIT) Index. Then, after MSM’s 2025 Top Operators Survey had ended, SmartStop acquired Argus Professional Storage Management (APSM) in a deal that closed on October 1^st. APSM ranked No. 16 in 2025, dropping six spots from 2024.

Ranking No. 8 is The William Warren Group, which operates facilities under the StorQuest brand; it ranked 13^th last year. In nineth is Storage Rentals of America (SROA), an operator that wasn’t listed in the 2024 list but has been ranked in previous years. It owns and operates nearly 32 million NRSF from 683 facilities across the United States, 12 in England, and three in Scotland. Other high-ranking newcomers to the 2025 list include White Label Storage at No. 13, City Line Capital at No. 15, and Absolute Storage Management at No. 25.

Finally, due to the addition of SROA and upward movement from The William Warren Group and SmartStop, as well as a slight decline in portfolio size, StorageMart has dropped from seventh to tenth.

As seen in Chart 2.1, market share of “Other Top Operators” ranked No. 6 to 100 is 14.3 percent of the industry’s total number of facilities. By rentable square footage, shown in Chart 2.2, their share is much more substantial at 27.1 percent.

When measured by the number of facilities, industry market share paints a better picture for the independent owner-operator. The number of facilities owned by the “Rest of Industry” (independent owner-operators who are not among the top 100 operators) is 66.4 percent this year, up half a percent (0.5 percent) from last year, as seen in Chart 2.1.

However, the Rest of Industry’s lead over REITs and Other Top Operators is negligible when calculated by rentable square footage. Chart 2.2 shows that Rest of Industry holds 37.3 percent of the market share by rentable square footage, which is only 1.7 percent more than the REITs but 10.2 percent more than Other Top Operators.

Having evaluated all 100 top operators, as well as the data specific to the REITs, let’s delve deeper into the list. Only non-REIT operators who own their facilities are addressed here. Management companies that only offer third-party management but do not own self-storage facilities are discussed later.

Minus the REITs, there are 40 companies in the list of 100 top operators with portfolios consisting exclusively of properties they own. The top 10 of these operators are listed in Table 2.3 and Chart 2.3, which show relative size based on rentable square footage.

See Table 2.3.

In the top spot is Storage Rentals of America (SROA) with more than 31 million rentable square feet. As indicated, Storage Rentals of America was not ranked on the 2024 Top Operators list. SROA is followed by Merit Hill Capital and Prime Group Holdings (Prime Storage), which have both dropped down a rank as a result of SROA’s inclusion on the 2025 Top Operators list.

Remaining in the No. 4 position is Derrels Mini Storage with nearly 21 million rentable square feet. Another newcomer to the list, City Line Capital, with 19.5 million rentable square feet, has landed ahead of Morningstar Properties, which is now No. 6. Morningstar Properties dropped one rank last year as well; it had ranked No. 4 in the 2024 Self-Storage Almanac. KO Storage also moved down a spot to make room for Amsdell Companies (Compass Self Storage); both companies have slightly more than 8.6 million rentable square feet, but Amsdell reported having almost 30,000 more square feet in its portfolio. Ranked 7^th last year, Mini Mall Storage, which has both American and Canadian facilities, is now No. 9. SecureSpace Self Storage, one more not ranked in 2024, has taken the No. 10 slot with more than 7.5 million rentable square feet.

The ranks are somewhat different when sorted by total number of facilities, as seen in Table 2.4 and Chart 2.4. While the No. 1 and No. 2 companies are the same (Storage Rentals of America with 683 facilities and Merit Hill with 406), City Line Capital comes in third for having five more facilities than Prime Group Holdings. KO Storage, ranked 8^th by rentable square footage, moves up to No. 5 by number of facilities. In the No. 6 position is Mini Mall Storage with 189 facilities; this is an increase of three ranks when compared to its rentable square footage ranking. With 116 facilities each, Morningstar Properties and Amsdell Companies are tied for No. 7, so they have been listed as 7a and 7b. Coming in eighth and nineth are two newcomers to the 2025 Top Operators list: Baranof Holdings and Safeguard Self Storage. They have 91 and 90 facilities, respectively. Rosewood Property Company takes No. 10 with 84 facilities. It should be noted that Storelocal Storage, which ranked 31^st on the 2025 Top Operators list, has been omitted from this list, despite reporting a portfolio of 90 properties, because it operates the brand within which independent owner-operator run their businesses; it does not own those properties.

See Table 2.4.

As previously mentioned, there are 17 companies on the Top Operators list that third-party manage facilities but do not own facilities. The top 10 of those third-party management companies by rentable square footage are seen in Table 2.5 and Chart 2.5. No. 1 again in 2025 is Storage Asset Management, which is also known as SAM; it reported a total surpassing 37 million rentable square feet. New to the 2025 list is White Label Storage, a national company with more than 22.5 million rentable square feet in its quickly growing portfolio. Dropping to third was Argus Professional Storage Management; compared to 2024, it reported approximately 3 million rentable square feet less in 2025. It’s uncertain whether Argus’ numbers will still be reported separately from SmartStop Self Storage for the 2026 Top Operators Survey. White Label Storage’s entry also bumped StoragePRO Management down a rank to fourth. StoragePRO has added approximately 338,000 rentable square feet to its portfolio in a year’s time. Moving up a spot into fifth is Space Shop Self Storage with 7,120,215 rentable square feet. In sixth is Atomic Storage Group, which had ranked No. 4 last year. Holding firm at No. 7 is TnT Self Storage Management with more than 6.2 million rentable square feet. Universal Storage Group lands eighth on the list, bumping Trusted Self Storage Professionals out of that spot and down to tenth. And with slightly more than 4.1 million rentable square feet is Right Move Storage, LLC at No. 9.

See Table 2.5.

Table 2.6 and Chart 2.6 show that there are few changes to the ranking of the top 10 management companies when sorted by number of facilities. The top four remain the same: SAM, White Label Storage, Argus Professional Storage Management LLC, and StoragePRO Management. The next four rankings have shuffled a bit. Atomic Storage Group is now fifth with 147 facilities. Universal Storage Group moves up to sixth with 89 facilities. With 80 facilities in its portfolio, Space Shop Self Storage drops to No. 7. TnT Self Storage Management also falls a spot to eighth. No. 9 and No. 10 remain unchanged: Right Move Storage with 64 facilities and Trusted Self Storage Professionals with 47 facilities.

See Table 2.6.

With every new self-storage facility developed, the market share gradually changes. On top of new development, much of which is operated by a third-party management company, consolidation reassigns ownership, often expanding the larger operators’ piece of the pie—sometimes by entire portfolios at a time.

Although new development has somewhat slowed compared to years past, growth of the REITs’ extensive portfolios has not. With more management contracts under their belts, smaller facilities being developed, and corporate consolidation of top operators, the shifting ownership landscape is deserving of attention. It will be interesting to see what 2026 brings!