Good morning, everyone. As many of you know, Gladstone Capital is the lending fund of the Gladstone Companies. We provide cash flow-based loans to privately held U.S.-based businesses in the lower middle market, which we define as having $20 million to $100 million in revenues and $3 million to $15 million in earnings before interest, taxes and depreciation. Our loans are used to fund private equity buyouts, make acquisitions, meet growth capital needs or to recapitalize or refinance an existing capital structure.
Gladstone capital was one of the first BDCs focused on lending to the lower middle market, established 2001, and today that dedication, experience and consistency are core part of our value proposition. We approach the market with an investor perspective and strive to deliver market-oriented capital solutions to support each business' unique capital and growth profile.
The majority of our loans today are the businesses backed by private equity sponsors and include a combination of secured first- and second-lien loans and may include an equity co-investment. We target to make investments of $8 million to $20 million, but will opportunistically consider smaller positions in broadly syndicated loans from time to time.
With that introduction, let's review our results for March 31st quarter and our outlook for the markets in which we operate.
Regarding investment activity, we are pleased to report that for our second fiscal quarter ending March 31, 2015, despite the usual low in new deal activity in the first quarter of the calendar year, we closed one proprietary deal and some follow-on investments, totaling $31 million of fundings for the quarter.
Additionally, we experienced minimal repayments during the quarter, so the new investments translate into net portfolio growth of $30.5 million or 7.9%. The new proprietary deal closed during the quarter was for Precision Metal Hose, a manufacturer of flexible metal and composite hoses used in a variety of industrial applications or supplied to OEM manufacturers serving the aerospace, defense, power generation, general industrial and oil and gas industries.
The financing included a $21 million of secured first-lien loan and a small equity co-investment and an unfunded working capital line of $4 million.
The financing was in support of the acquisition of the company by a local private equity sponsor, which represented GLAD's first deal with this sponsor. The closing leverage of the deal was a modest 3.5 turns of leverage and the deal yields 9.3%.
Additionally, we had $9.7 million of follow-on investments in existing portfolio companies during the quarter, including a $6.6 million advance to Lignetics to fund an acquisition which enhances the company's market coverage and economies of scale.
With respect to the portfolio overview and performance. In the past 2 quarters, the cumulative effect of our focus on secured first-lien investments has begun to impact our portfolio mix and results. And for a greater details, we'd recommend you review our updated investment portfolio disclosures in our recently released 10-Q. The highlights of the portfolio show that 91% of our investments in the last 2 quarters were lower-leveraged first-lien unitranche transactions. As a result, our first-lien investments have risen almost 10 points from 46.6% of our debt investments to 56.1% of total debt investments at fair value. The balance of our debt portfolio was second-lien investments, including a combination of proprietary and syndicated second-lien loans, as we do not have any unsecured subordinated debt exposures. The consequence of this asset mix shift has a number of implications, and we will touch on them over the balance of this call.
On the whole, the fair value of existing portfolio increased by $6.5 million on the quarter, as unrealized appreciation of $14.1 million exceeded unrealized depreciation of $7.6 million. The largest 3 drivers of the unrealized appreciation for the quarter represented 74% of the increase and included the $6 million appreciation of our equity position in Funko, a toy company that provides pop-culture collectibles, pursuant to licenses, which is continuing up to a very strong operating performance.
Other notable valuation improvements included: Precision Acquisition Group, which was up $2.3 million and is benefiting from the recovery in aluminum production; and Sunburst Media, which we're hopeful to make an opportunistic upcoming sale of the underperforming radio station, which was up $2.1 million of appreciation this quarter.
Partially offsetting these movements, unrealized depreciation included $2.5 million associated with the rapid performance deterioration and in sewing restructuring of our syndicated second-lien position in PLATO learning, which was reduced to 35% of cost.
In addition, the continued underperformance of GFRC, the commercial buildings products manufacturer, represented a decline of $1.8 million, and $1.1 million of depreciation was associated with the external valuation of our oil and gas investment positions.
With respect to our oil and gas exposure, there were no material changes on the quarter. The industry exposure represents $51.7 million or 14.2% of our portfolio at fair value and continues to perform well. To recap our sector exposure: 59% of the exposure was related to downstream services, which are not directly impacted by crude prices; the debt positions are conservatively leveraged with weighted average leverage of only 2.6x EBITDA and average fixed charge coverage of 3.4x. All companies are covenant compliant, have ample liquidity to absorb any margin or volume pressures and are backed by strong and experienced private equity sponsors.
Cumulative unrealized depreciation associated with our oil and gas loan portfolio totaled $3.4 million as of March 31, and the fair value represents 93.5% of cost. On the whole, the cumulative net unrealized depreciation of investments declined to $52.7 million for the quarter ending March 31st. And this improvement represented the bulk of the increase in NAV from $9.31 to $9.55 for the quarter.
Despite some successes on the quarter, our nonaccrual investments and underperforming assets are still higher than we consider acceptable. This quarter, we added GFRC as a nonaccrual investment, as operational issues have continued to undermine the company's financial performance. The fair value of the GFRC investment was reduced to $2.2 million this quarter, and we exercised our creditor rights and have taken control, hired a CRO, who has stabilized the operations, and we are assessing our exit options.
With respect to one of our larger challenge credits, Sunshine Media Holdings, the company's improved profitability and liquidity supported our moving certain tranches of our investment to accrual status beginning this quarter.
As of March 31, 2015, our combined nonaccrual debt cost basis is $39.2 million or 10.2% of the cost base of all debt investments in the portfolio and has a combined fair value of $9.2 million or 2.8% of the fair value of all debt investments.
We are currently working to exit a number of our legacy underperforming assets, and while we cannot discuss specifics, we are working -- we are looking forward to be able to update you in the near future. That said, while we have had some successes in turning around or exiting several of our nonaccruals and more challenge credits in the past year, with favorable results, this does not mean that we can do it again or that we'll not place other companies in nonaccrual in the future.
With respect to our portfolio yields, moving over to our portfolio income profile, the weighted average yield on interest-bearing debt investments, excluding reserves, in our portfolio was 11.3% as of March 31, 2015, which was down from 11.5% as of September 2014. This drop is directly related to the cumulative effect of the increase in lower-leveraged, secured first-lien investments funded by increased draws under our credit facility. For the quarter, investment income was up 14.3% or $1.1 million compared to the prior quarter and compared to the increase in interest expense of $346,000.
Our debt portfolio was well positioned for any interest rate increase, with 85% of the portfolio in floating rate investments and 15% in fixed rate investments. Our floating rate investments typically have a minimum or LIBOR floor, and the weighted average floor in our variable rate loans was 1.9%. While the weighted average margin is 9% as of March 31, 2015, our proprietary loans totaling 82% of the total portfolio cost had a weighted average yield of 11.3%, while our syndicates totaling 18% of the total portfolio cost had a weighted average yield of 11.1%.
Our other income has been significant at times over the last several quarters, which is primarily due to what we call success fees, which are fees generally due upon the change of control of the company are recorded when received in cash. We received over $500,000 in success fees during the 3 months ended March 31, 2015, which is down from the prior quarter ended December, which totaled $880,000. We track our success fees off balance sheet due to their highly contingent nature, and as of March 31, 2015, the off-balance sheet success fee receivables totaled $11.4 million or about 54% -- $0.54 per common share. In total, other income was down $595,000 versus the prior quarter and offset much of the increased interest spread generated by the higher average asset levels.
In addition to what we believe to be the favorable risk return profile of a recently originated secured first-lien unitranche investment, this asset shift is also -- was made in anticipation of the amendment and extension of our credit facility. The revised facility, which is closed and was announced earlier this week, will both reduce our borrowing costs by 50 basis points across the board as well as increase the advance rates against our secured first-lien assets, thus significantly improving our return on equity on these assets.
With respect to the investment climate backlog of loan opportunities and outlook. While new transaction opportunities in the first quarter were relatively light, more recently, activity levels across the lower middle market have recovered, and we're currently working on a healthy pipeline of proprietary deals. We continue to see a proliferation of smaller, newly formed PE firms looking to take on smaller investment opportunities, with increased emphasis on buildup or acquisition investment strategies. These trends are well suited to our lower middle market focus, value proposition and focus on delivering senior secured unitranche financing solutions.
From a liquidity perspective, going into the balance of 2015, the competitive dynamics for middle market loans are mixed. Several factors continue to suggest the tightening of the market, including: the cumulative impact of the regulatory pressures on leveraged lending by the banks; weak BDC stock performance to the point that many are trading below NAV, which service less in the competition, to book middle market loans; and obviously, uncertainty associated with the GE Capital's announcement to exit the leveraged financing business.
The relatively weak flow of deals thus far in 2015 has, however, still competitive pressures with a few quality investment situations. Competitive pressure continues to be most pronounced in the larger end of the middle market, north of $10 million of EBITDA, where the commercial banks and broadest array of nonbank lenders operate. In the face of this competitive profile, our strategy continues to leverage our long-standing reputation in the lower end of the middle market and investor-oriented financing approach and continues to gain traction. We're focused on investing in our coverage of relationships with the private equity sponsor community and expect to be able to continue to source attractively priced unitranche transactions in the lower middle market.
Our continuing priorities for the balance of our fiscal year ended 2015 will be: managing our remaining challenging credits in the portfolio to an orderly liquidation events, where possible; utilizing enhanced availability under the recently emended line of credit; and sales of our syndicated loan position or select first-lien positions to support the future growth of our proprietary debt portfolio.
And now, our Chief Financial Officer, Melissa Morrison, will provide an update on the fund's second fiscal quarter financial results.