Stocks have turned up since the end of October, buoyed by an election that may offer stability and by news that effective vaccines for the novel coronavirus are closer than we had dared to think. The quick market shifts are enough to make investors dizzy – or at least, to get them looking to the experts to make sense of the financial landscape.In times like these, the legends can offer some guidance. We are referring to the people that transformed the way we play the investing game, namely Ken Griffin.Ken Griffin has a talent for math and finance. Since he started stock trading from his Harvard dorm back in 1987, Griffin has built up a personal fortune of more than $15 billion – and made a reputation on Wall Street as a giant in the hedge world. While he is personally reclusive, his investment decisions remain public, and following Ken Griffin’s stock choices makes a viable investment strategy.Griffin notes the market fall last winter, and describes the general rebound since March as “a macro trader’s dream.” Looking at the election, he sees the results as a net positive for the markets. Divided government, he believes, along with a narrower Democrat majority, will empower the centrists and help avoid “crippling” tax increases. With this in mind, we wanted to take a closer look at three stocks Griffin’s fund Citadel picked up recently. Running the tickers through TipRanks’ database, we learned that each one boasts a “Strong Buy” consensus rating from the analyst community and massive upside potential.Kadmon Holdings (KDMN)First up we have Kadmon, which focuses on developing drug treatments for immune disorders and fibrotic diseases, and like many clinical research companies, the investment point here is all about potential rather than earnings. Kadmon has two drugs in the pipeline – Belumosudil (KD025), which is in late-stage testing as a treatment for chronic graft-versus-host disease (cGVHD) and systemic sclerosis; and the experimental KD033, which is being investigated as an immunotherapy for cancerous tumors.A New Drug Application (NDA) has been submitted to FDA for Belumosudil in cGVHD, and is currently under review. Meanwhile, a phase 2 systemic sclerosis study continues to enroll and a small open label Phase 2 study is expected to start in 1Q21. Furthermore, KD033 is currently in Phase 1 study in metastatic and/or locally advanced solid tumors.An active pipeline – especially one in which the drug candidates are advancing steadily – is sure to attract investor attention. Among the fans is Ken Griffin. 924,309 shares were bought up by Citadel in Q3, with the total position now landing at 6,587,531 shares. The position is valued at more than $24 million.Covering the stock for Mizuho, analyst Mara Goldstein noted, “Belumosudil, a novel ROCK2 inhibitor, successfully completed a pivotal program (ROCKSTAR) in chronic graft versus host disease and a submission to the FDA has been initiated. We see this indication as generating U.S. revenue of $628 mln in 2030, which is not fully appreciated in KDMN’s valuation, in our view […] We also see potential opportunity from additional indications and other candidates holding valuation inflection potential.”To this end, Goldstein rates KDMN a Buy along with a $13 price target. This target conveys Goldstein’s confidence in KDMN ability to climb 246% from current levels. (To watch Goldstein’s track record, click here)Are other analysts in agreement? They are. Only Buy ratings, 4, in fact, have been issued in the last three months. Therefore, the message is clear: KDMN is a Strong Buy. Given the $13.75 average price target, shares could skyrocket 266% in the next year. (See KDMN stock analysis on TipRanks)K12, Inc. (LRN)Next on our list of Griffin picks is K12, a company in the education management organization niche – or in other words, a provider of school curricula and educational resources designed for online learnings as an alternative to traditional brick-and-mortar school systems. K12 was founded in 2000, but has come into its own during the corona crisis of 2020, when social lockdown policies shunted students toward homeschool and online venues.The numbers show it, as far as they can. K12 reported Q3 (FY Q1) revenue of $371 million, up 37% from the prior quarter and an even more impressive 44.3% year-over-year. The company’s general education business accounted for $313.8 million of that total, and was up 34.4% year-over-year. EPS jumped 150% sequentially, from 12 cents in Q2 to 30 cents in Q3.Clearly, Griffin understood K12’s potential in the current environment, as he purchased 447,703 shares of LRN during the third quarter. Griffin now owns over 496,000 shares of the company, and this holding is worth almost $11.9 million.Taking a bullish stance on this stock is analyst Alexander Paris, of Barrington. Paris writes, “Management is cautiously optimistic it can grow as it focuses on student retention (which has consistently improved over the last several years) and its career learning initiatives… investors have been drawn to its robust distance learning model and see potential upside from COVID-19 driving demand for its services over the intermediate to longer term.”In line with these comments, Paris rates the stock an Outperform (i.e. Buy). His price target of $60 shows his confidence in a 150% upside for the coming year. (To watch Paris’ track record, click here)Once again, this is a stock with a unanimous Strong Buy consensus rating, supported by 4 recent analyst reviews. The shares have an average price target of $49.33, suggesting a 106% upside from the trading price of $24. (See K12 stock analysis on TipRanks)Overstock (OSTK)Overstock is an online retailer that got its start in the wake of the dot.com bubble twenty years ago; ironically, it started as an e-commerce company selling off the inventory assets of failed e-commerce companies. Today, Overstock is still involved in the closeout segment, but also sells new goods in the bedding, furniture, and home décor niches. In the most recent quarter, Overstock beat the estimates on earnings and revenues. EPS was expected at a 22-cent loss, but came in at a profit of 50 cents. On the top line, revenue grew 110% year-over-year to reach $731.7 million. Obviously, Overstock has benefitted from the corona pandemic pushing more retail online, and OSTK shares have benefitted, too. The stock is up an astronomical 707% year-to-date, even after slipping significantly from its late-August peak value.A discount retailer with a strong online presence is a clear opportunity in the current climate, and Griffin took advantage of it. His new position is OSTK totals 110.281 shares, currently valued at $6.3 million. Writing for Piper Sandler, 5-star analyst Peter Keith notes, “[T]rends in Q4 “remain strong”, suggesting to us that continuing ~100% growth in the qtr is quite possible. New customer growth was +141% y/y, and OSTK saw sequential improvement in its new customer repeat purchase rate.”The analyst concluded, “Valuation at <1.0x NTM EV/S looks very cheap to us, especially considering that a ~$490M net cash position, representing ~18% of market cap. We would be aggressive buyers of the stock at current levels.”Keith gives OSTK an Overweight (i.e. Buy) rating, and his $140 price target implies a 145% upside for the next 12 months. (To watch Keith’s track record, click here)All in all, Overstock’s Strong Buy consensus rating is based on 4 Buys and 1 Hold. The stock is selling for $57.10 and the $101 average price target suggests it has a 76% one-year growth potential. (See OSTK stock analysis on TipRanks)To find good ideas for stocks trading at attractive valuations, visit TipRanks’ Best Stocks to Buy, a newly launched tool that unites all of TipRanks’ equity insights.Disclaimer: The opinions expressed in this article are solely those of the featured analysts. The content is intended to be used for informational purposes only. It is very important to do your own analysis before making any investment.